The ultimate travel etiquette experts' guide to the unwritten rules of travel: Should children, the elderly, disabled or pregnant get the priority seat? Should young men be first to give up their spot? And can I scold parents with a crying baby?

An airline passenger who refused to move in first-class for a six-year-old whose mother failed to book a nearby space for their child is the latest big travel bust up to hit the headlines.

With the summer holidays well underway, horror stories about blazing rows on planes, trains and buses over seats, excessive noise and drinking are also all over the news.

Here MailOnline reveals the ultimate travel etiquette guide with the help of three of the world's leading experts.

Today these authorities on the subject give definitive answers on burning questions including whether a man should always stand up for a woman and who deserves a seat more out of a pregnant woman, the elderly, the disabled and children.

They also have the last word on at what point in a flight it is acceptable to start drinking, whether it is fair to recline seats or lift armrests on planes at all and when and how it is best to intervene with parents if their child is screaming, or watching loudly on a tablet or phone with no headphones.

Should a plane passenger refuse to give up a first-class seat so a child can sit with their mother or father?

The debate over travel etiquette exploded after it was revealed how a plane passenger refused to give up her first-class seat so a six-year-old boy could sit with his mother.

The airline seat incident emerged on Reddit's popular 'Am I The A**Hole' thread – and has opened a can of worms.

Etiquette guru Sarah Jane Ho, host of the Emmy-nominated Netflix series Mind Your Manners, told MailOnline today that she agreed with the passenger who refused to budge.

She said unless a child is very young - or difficult - they 'can sit on their own because it's not like they're going to get lost on a plane'.

'A parent should think of these things in advance and seat their kids with them when checking in', she said.

If an old person gets on a bus at the same time as a disabled person or pregnant woman - who should get a priority seat? 

When people ride buses there can be a case of musical chairs as people stand up and move when pregnant women or the disabled get on board.

On other occasions there are just steely, cold stares from those people who refuse to move from their seats for someone older or less mobile - with culprits often looking down at their phones or out of the window to avoid contact.

Etiquette expert Philip Sykes, Founder and Principal of the British School of Excellence, believes there are clear social rules about who people should move for.

'I feel the priority should typically go to the disabled person or pregnant woman, as they may have a more immediate need for seating', he told MailOnline.

But others believe that it should be less rigid and left to judge the situation. 

Jo Bryant, a leading etiquette expert and tutor offering courses in British etiquette including travel and dining, said: 'If you are sitting in a priority seat, be ready to move and give it up to someone else more in need both willingly and quickly'. 

And should children get somewhere to sit over the pregnant and disabled? 

A relatively new trend has been to treat children, not just those carrying a child or disability.

MailOnline's etiquette panel are largely clear: children shouldn't come first - but also it women who are in the early days of pregnancy shouldn't expect a seat either.

Philip Sykes said: 'I feel that pregnant women and disabled individuals should be given priority for seats over children, as their need for seating is generally greater. If the parents have a seat, their children can sit on their laps'.

While Netflix star Sarah Jane Ho said: 'I'm not sure that a pregnant lady or a disabled person should be kicked out of their seats for a child. 

'And I guess, you know, with pregnant women as well, it depends on long depends how far along they are. If, you know they're sort of up to three months, not even showing, I mean, it might be harder to make a case. 

'But if they're like seven or eight months and really about to pop and they're waddling around and they're uncomfortable, the last thing you want to do is make those make them even more uncomfortable by shifting them around. 

'Same thing with a disabled person. I mean, like a disabled person really comes first to the top of the of the top of the pecking order'.

But Jo Bryant said it should be done on a case by case basis.

'The priority seat should be given to the person who needs it the most. This is a a matter of common sense, consideration and honesty', she said.

Should I intervene if I think someone should give up a seat for a pregnant, elderly or disabled person? If so, what is the politest way to do it? 

Sarah Jane Ho says the decision to intervene 'depends on how close you're sitting'.

If you're sitting like on the same row, or the one in front or behind then it is acceptable to say something.

But being a 'nosey parker' and chipping in from further afield isn't.

She said: 'Let's say you are sitting in that area. And you feel strongly that somebody should have this seat. First, if you're being such a gentleman or gentlewoman, you could give up your seat. Be the role model, right? That's what I've done. When I see an older person that's a on the subway and they don't have a seat. First thing I do is I jump up and I say "please take my seat". 

'Firstly, it should come from within. But if you don't have a great seat but you think somebody else should move.  'Let's say it's a young person. A young man, you can say something like: "Ah, why doesn't this nice young gentleman here give up your seat for this disabled person?" 

"So if you couch it in a way that is complimentary, and sort of fun, as opposed to critical and judgmental, then that is the best way to do it'.

'Or you could say: “Excuse me, would you like to sit here?” This keeps the situation respectful and avoids any potential conflict'.

Philip Sykes agrees.

Passengers can say something as long as it doesn't cause conflict.  

He told MailOnline: 'Yes, you can intervene politely. The best approach is to address the person who should be offered the seat directly rather than confronting the seated person. 

'You could say, “Excuse me, would you like to sit here?” 

'This keeps the situation respectful and avoids any potential conflict'.

Should men stand up for women and offer them a seat? 

Is chivalry dead?

Many think so, although etiquette experts do still think that it is a good thing when men stand up for women to give them a seat. 

Sarah Jane Ho says: 'I would say that tradition would say yes, feminists would say no, I'm somewhere in between. 

'But if a man is going out of his way to be a gentleman by offering his seat then I'm  impressed and I'm grateful'.

But she also says that age is a factor.

'I often say that etiquette is about context. There's no black or white. And, I mean, if it's like a really elderly gentleman if it's like you know, grandpa or somebody who was in the 80s or 90s, well, then he's geriatric, and he should not have to go out of his way. If it's a young man in his 20s or 30s, and and the woman is old, then you know, he should go out of his way', she said.

Jo Bryant says gender is irrelevent now. 'Gone are the days when men were required to give up seats for women; today, anyone should offer their seat to someone who needs it more than them, regardless of gender', she said.

Should passengers be able to eat what they want on planes or public transport?

Nothing can be more unpleasant than the stench of strong food on packed public transport. 

Sarah Jane Ho says that people should even think about the kind of fruit they eat around others.

She said: 'Strong smelling pungent foods in any kind of enclosed space, whether it's on a plane, on a train or even in your office should be a no no' - citing curry and fish.

She went on: 'Things that do not do not have a strong smell and and will bother other people. Even some fruits like oranges have a strong smell and even though oranges smell kind of nice, but not everybody may like oranges that remember in these enclosed spaces. It's not like you could open a window on an airplane or most trains'.

Philip Sykes cited the ban on strong-smelling in foreign countries. 

'It is considerate to avoid eating strong-smelling food on trains to prevent discomfort for other passengers. In Hong Kong, food and drink are banned on public transport', he said.

Jo Bryant is in agreement.

She said: 'Avoid eating smelly foods on trains; pungent smells from meal and snacks are amplified in a train carriage, so think about your choice and opt for something that won’t be unpleasant or overwhelming for fellow passengers'.

Should nuts be banned on buses and trains, as well as planes? 

The family of a teenage girl who died after suffering an allergic reaction on a plane today demanded airlines clamp down on passengers eating peanuts - after another girl passed out at 30,000ft over her nut allergy.

Natasha Ednan-Laperouse, 15, died in 2016 after suffering an anaphylactic shock to sesame seeds in a Pret a Manger baguette she had bought at Heathrow before catching a flight to Nice.

Some airlines have banned nuts from flights completely. Others read out a warning before take-off if someone on board has an allergy, 

Outspoken Ms Ho has said believes that airlines have gone 'too far' with blanket bans on nuts and passengers should be able to eat them unless there is someone with a known severe allergy on board. 

She said: 'Peanuts are the largest cause of food related deaths and if somebody has an allergy the last thing you want to be is on a plane because you don't have access to the hospital. 

'So if elements wanted to completely eliminate the risk of not allergy shocks or deaths, then they can just not serve it, but I think it's going too far now.

'Because if somebody else wants to bring their own nuts onto the plane, they should have the right to bring them and take them'.

Philip Sykes says that a blanket ban is sensible.

He said: 'Yes, I feel they should be banned due to the fact that nut allergies are very serious; in turn, it would protect passengers with severe allergies and prevent potential allergic reactions in confined spaces. 

'You may recall the tragedy on the Easyjet flight a few years ago, where a person died from a sandwich prepared at Pret a Manger - known as Natasha's Allergy Law'.

Should families with children be allowed to go to the front of the queue when boarding a flight? 

Some have said that one of the oddities of plane travel is letting on families with children first.

MailOnline's etiquette experts are split.   

Philip Sykes said: 'In my opinion, this does make sense for families with young children to board first to allow extra time for settling in and storing luggage. This, in turn, will also benefit other passengers by reducing overall boarding congestion and delays'.   

But Jo Bryant disagrees. 

'There is no need to queue-barge with kids. Airlines usually offer families the option of a designated boarding time, often first, or if not, you must wait until your row is called. Boarding early with kids isn't always the best idea - some savvy parents prefer to board later, preventing children from sitting on the plane for longer than necessary and getting bored before take off', she says.

Is there an acceptable time on a flight to recline your seat? 

People have the right to recline - but should choose when carefully.

Philip Sykes says that air passengers should wait until everyone has eaten if people are having a meal on board.

He said: 'It’s courteous to wait until after the meal service is over before reclining your seat. 

'I would always suggest you recline slowly and check behind you to ensure the passenger behind is not inconvenienced'.

Sarah Jane Ho says the ruled are clear that 'you're not allowed to recline your seat as takeoff or landing'.

But added that it's fine after that.

She said: 'If you want to recline, you can recline your seat when the plane is not at an angle - ie when it's going up or it's going down, because then it's just uncomfortable for the person behind you.

'But if it's flat, then you can recline. You can recline your seat. Remember when when you do it, don't do it suddenly, because you don't know what the person has behind you behind you. You want to do it smoothly and gently'.

Plane armrests: When should they come down - and who gets ownership of the middle seat ones?

Experts say that armrests should never be raised - unless you are with family or a loved one.

But anyone in the middle on a row of seats has the worst seat so should get the armrests to themselves.

'Armrests are usually down on takeoff and should remain down for the duration of the flight for comfort and separation of space. In my opinion, the person in the middle seat typically has the right to both armrests, as they have the least space', Philip Sykes said.  

Sarah Jane Ho added: 'The person sitting in the middle seat tends to have a worse seat. So they usually get both armrests. 

'And on armrests: as long as you're sitting next to a stranger they should always be down. Because do you really want to basically share seat with a stranger? I don't think so. Right? You need that divider. That's what the armrest is. 

'If you're traveling with your significant other or family member and you want to have a bit very close to each other, then you don't have to put the armrest down but if it's a stranger put it down'. 

In the day and age of having to book specific seats for extra cash on many airlines, can you ask to move to a different empty seat once on board? 

Yes, absolutely.

Philip Sykes says: 'You can ask to move to an empty seat once the plane is in the air, but it’s courteous to wait until the plane has reached cruising altitude and to ask a flight attendant for permission. 

'This ensures there are no last-minute seating adjustments needed and respects the booking system'.

Sarah Jane Ho says that you should stay in your seat and not disrupt boarding before moving.

'Let's say there were like rows and rows of empty seats. You have to wait till the doors closed. The last thing you want to do is to be switching seats around with the doors not closed yet. 

'That's just annoying for everybody. So you wait until the plane doors are closed. And then ask the air steward or stewardess: "Can I move to that row?" That is fine because you're not bothering anybody'.

Is it 'cheeky' for newlyweds or people flying for a special event to ask for an upgrade on a plane?

Airlines are well used to being asked for a class upgrade by newlyweds.

But in fact there are more people asking becaiuse of birthdays, special holidays and graduations, for example.

Etiquette experts say that as long as passengers ask with charm - they are ok to 'try their arm'.    

Philip Sykes said: 'It really boils down to asking with charm and good manners - chancing your arm a bit. As we all know, the upgrade is not guaranteed; I do know that some airlines sometimes accommodate these requests if space and policies permit, but there's no obligation for them to do so. 

'It's generally seen as a goodwill gesture rather than a standard expectation. Again, in my opinion, airlines could dine out on this offer, especially if there is space for the honeymooners. In turn, the honeymooners will rave about the airline, what a lovely story to tell'. 

Jo Bryant agrees - people should feel comfortable with asking - but it should be in a nice way.

'Why not? As long as it’s done politely, with the awareness it’s a ‘cheeky ask’ – you can only be refused', she said.

Is putting a bag on a seat on an empty seat okay? If a passenger does it - should they have to pay for an extra ticket? 

It is a scene repeated on every train, bus and sometimes even planes around the world.

A passenger places their bag on the seat next to them - often to stop someone sitting there.

Sometimes on a quieter day, there are plenty of seats to go around. But on busier services - the fireworks can fly.

One of MailOnline's experts believes that if you want a bag on the seat next to you, you need to pay for it!

Philip Sykes says simply: 'If someone wants to occupy a seat with their bag, they should purchase an additional ticket to account for the space'.

But Sarah Jane Ho and Jo Bryant say that no one would believe you if you said you had a ticket for your bag.

Ms Ho said: 'Well, listen, if there's nobody sitting next to you, you can put your bag on the seat. 

'But if I mean it, just bizarre, I don't think you should have to pay an extra ticket. But also, I don't think you should be putting your bag on your seat. 

'If there's nobody, if there's somebody sitting there, right. If it's somebody's seat, like, that's somebody's seat. But if it's an open seat, then yeah'.

She says it is also ok on a plane. 

She said: 'I'll be in an aisle. There'll be a person on a window, and then there'll be a middle seat that's open. Both of us will put our hand back, so that's totally fine'. 

But Jo Bryant says it is not convinced.

'Bags shouldn’t be stored on seats unless you have the luxury of an empty carriage or bus etc. Put them away in luggage racks, on the floor or on your lap. No one will believe or realise you have bought an extra ticket for your bag, so best be practical and store it sensibly and considerately instead', she said.

Are there any circumstances where it is acceptable for someone to put their bags in the aisle of a train?

No.

Sarah Jane Ho goes further, and says that you should store luggage safely and always where you can see it. 

'The aisles should always remain clear. You're supposed to put it at the end of the carriage. Make sure that if you do that you sit in a direction facing where your bag is because with with thieves these days.

'I've had friends where we've been on the train in Switzerland or in the UK, and they put the bags in the back of the carriage. They sat in a way where the bags were behind them and lo and behold, the bags was stolen'.

Philip Sykes says that it doesn't matter how busy a train is, luggage in the aisles is not acceptable.

Even if it ends up on your lap. 

'Leaving bags in the aisles of a busy train is generally not acceptable as it can obstruct movement and pose a safety hazard. Always store bags in the designated luggage areas or keep them with you without blocking the aisle. There are usually overhead racks and, on some trains, specific areas for luggage', he says.

Can you sit in first class if the rest of the train's carriages are full? Is it even acceptable on a plane?  

Another question many commuters ask themselves - sometimes daily - is whether they dare sit in first class if standard is fill. 

The experts are split.

Philip Sykes says: 'No, you should not sit in first class unless you have a first-class ticket, regardless of how full the other carriages are. I have been on a few train journeys where the trains were full, and the guard offered to passengers that they may occupy the empty first-class seats; that is thoughtful and kind'. 

Jo Bryant agrees that you should wait for guidance.

She said: 'If the area is declassified and it has been announced so, then go for it. Otherwise you obviously risk a fine if you don’t have top ticket'. 

But Sarah Jane Ho is more open to the idea.

'Well, I don't think it's up to you to decide if you can sit in first class if the standard carriages are full', she said.

She also believes that there is even a chance to go to first class on a plane. 

'If the plane is full, then you know they won't be allowed on but if there are no shows and they will be allowed. So let me just say it's not up to the traveler, where they sit. It's really up to the or the air stewardess to decide'', she said. 

Is it acceptable to decline someone’s request to switch seats? What’s the best way to decline a request?

The debate around swapping seats still rumbles on. 

Many passengers are certain they'd never give up their assigned seat - but  others much more willing to move.

However, according to Sara Jane Ho, declining a seat-swapping request is perfectly acceptable. 'You are not obligated to switch seats with anyone,’ she says.

Of course, she explains, this depends on which seat they want to move to. 'If it’s better, take it gladly. If it’s worse (like a middle seat) then you are justified [to decline].'

Sara advises to politely brush it off. 

'"I paid a lot for this seat, thank you for understanding,"' is a good dismissal, she claims. 'Nobody knows exactly how much you paid anyway.'

She adds: 'Or you can say, "32G is my lucky seat, I always have to fly in this seat otherwise I get anxiety."' 

Is there any good reason to ask to swap seats on public transport? For example if you have longer legs 

Experts say that asking to swap seats on a train or bus where no seats are reserved is fine when done politely - but don't be offended if your request is declined.

Experts say that asking to swap seats on a train or bus where no seats are reserved is fine when done politely - but don't be offended if your request is declined.

Sarah Jane Ho says that the person in the seat you want has every right to refuse if they were there first.

She said: 'If it's public transport, technically, you're not assigned seats. But that means technically it's first come first served.

'So if somebody first got there and has a seat, then they that is their seat. You don't really have a right to kick them out of their seat. You can always ask I mean if you don't ask, you don't get but you should not feel entitled'.

Philip Sykes believes there is no harm in asking.

And in fact the person in that seat should perhaps be proactive themselves if sat next to someone very tall.

'It’s acceptable to politely ask to swap seats if you have a legitimate reason, such as needing more legroom or easier access to the toilet. Simply explain your reason and be understanding if the other person prefers not to switch.

'On the other hand, passengers could be observant and offer a taller person their seat if it were doable', he said.

How should passengers deal with someone else's noisy or upset children?

Cacophonous children are almost a given on public transport.

To quieten them down, Sarah Jane Ho advises non-verbal communication to begin with.

'Eye contact should be enough of a warning,' she says. 

'If it really is getting out of hand, you can try to come across as though you are giving advice [to the parent] out of the goodness of your heart. [With babies, for example] something like, "Poor baby, do you want to try changing their nappy?"'

And her message for parents. 

Sara says: 'Look apologetic and at least appear to look like you’re trying to pipe them down.'

Is it ever acceptable to play something on a phone or iPad without headphones on planes and trains? 

There has been a plague of people blaring out music and videos using their phones.

All over the country Britons squirm in their seats as they ponder intervening.    

When up in the air or in the middle of a long train journey, passengers may want to unwind by watching a movie or listening to music on their devices. 

But, there's one thing they should keep in mind.

According to Sarah Jane Ho: 'It's never okay to have your phone on speaker phone in public. Wear headphones if your volume is on. 

'It is unacceptable. For anybody child or adult to watch stuff on public transport loudly. 

'It smacks of lack of consideration and respect for the people around you. And unfortunately this does happen a fair bit.

'I believe public transport is not as bad as in enclosed space such as on the plane or the train. 

'If let's say the subways are ready loud, noisy and rattling anyway, then okay if you have it on low volume, so that it's so that not everybody can hear it. 

'Maybe just you and the person listening to left or right can hear it. I mean that's still borderline and still not great. But if you're in a quiet closed area, then absolutely no sounds'.

Philip Sykes says that children can listen without headphones if it keeps them calm and quiet. But not so it disturbs others.

He said: 'It’s generally considered courteous for children to use headphones when watching iPads on public transport. This minimises disturbance to other passengers. 

'If headphones aren’t available, keeping the volume very low is a considerate alternative. However, I still feel that it should not be a loud'.

Drinking alcohol on trains or the Tube? Is it ever acceptable?

Experts believe it is acceptable on trains if it is allowed - but getting drunk isn't.  

Philip Sykes said: 'Follow the specific rules of the transport company you are using. If alcohol is allowed, drink responsibly and be mindful of your fellow passengers. It's never acceptable on the Tube, where it is banned'.

Sarah Jane Ho added: 'I think it's acceptable - if you don't get drunk.

'Of course, not everybody is able to control themselves. Listen, if it's a beer, some people want to kick back with a beer. So this is really just up to the company and what their policy is'.

And what about drinking on planes: What stage of a flight can you start hitting the booze?

Philip Sykes says drinking from the start of the flight is completely acceptable - but don't let it go too far. 

He said: 'Drinking alcohol on planes is generally acceptable and often served by the airline. It’s appropriate to start once the beverage service begins, usually after takeoff. 

'Always drink responsibly and be mindful of your fellow passengers. The crew have the authority not to serve alcohol if they deem it to be an issue with a drunk passenger'.

But Sarah Jane Ho is less supportive - if a person can't handle their drink. 

'To drink on planes is legal right now and it is acceptable. But remember, it's not actually good for you because on a plane you're dehydrated. 

'And as you climb higher and higher and the altitude in the bubbles will have the alcohol will have a bigger and bigger effect. It's highly not advised, especially for your own health. 

'But hey, it's your choice - as long as you're able to control your liquor and not get rowdy or emotional'. 

What should you say to someone talking loudly to their companion in a quiet carriage of a train? Is there any recourse I should take if it continues - or should I silently fume?

'Start with a polite request: “Excuse me, this is a quiet carriage. Would you mind keeping your voices down?”, says Philip Sykes.

'If the noise continues, you can seek assistance from a train attendant to handle the situation, as they are trained to enforce carriage rules'.

But if the problems continue - it is ok to push for people to be ejected. 

'I was at a cinema a month ago, and the three people in front of us kept talking and looking at their phones. Having been asked at the beginning of the film to turn their phones off and keep quiet during the film, I asked them twice to refrain, to then be sworn at. So I got up and informed the officials, who in turn informed security, and they were removed', he said.

Ms Ho says that a polite way to confront it is to claim you were asleep. 

'This is one of my pet peeves. I will actually just look over I will make eye contact which usually you know, when they catch your eyes, they should have the wherewithal to lower their voice. Or I say, I say excuse me, "I'm trying to take a nap and I can hear every single word of a conversation and this is the quiet carriage. Do you mind? Do you mind you know lowering your volume?" 

But she says move yourself if you can if people are being too loud in a normal carriage.

She said it happened to her on one occasion.

'This American man had a full on loud conversation that the whole carriage could hear, unfortunately, I was sitting on the same row as him and I was fuming. 

'But you know what? I wasn't in the quiet carriage so I couldn't quite say anything. What I ended up doing was moving to the quiet area'.