Hunter Biden got Lunden Roberts pregnant and heard their baby's heartbeat before having sex with her friend ... and then made a bizarre demand

Hunter Biden had drunken sex with Lunden Roberts' friend after he found out she was pregnant with their child and after listening to a recording of the baby's heartbeat.

In her forthcoming book - Out of the Shadows: My Life Inside the Wild World of Hunter Biden - Lunden the mother of 5-year-old Navy Joan, described Hunter's erratic and devastating behavior after she revealed her pregnancy to him.

In astonishing revelations Lunden recalls how one of her best friends in Washington D.C. confessed to a booze-fueled hookup with Hunter after 'falling victim to his charm.'

Incredibly, moments after she told Lunden about it, Hunter called the friend and both women then dramatically put the future First Son on speakerphone.

Shortly afterwards, Hunter met up with Lunden, but instead of immediately apologizing for sleeping with her friend, he bizarrely asked her for money to buy a Gatorade from CVS.

While Hunter initially signaled that he'd be supportive of Lunden's decision to have their baby, the former crack cocaine addict's behavior quickly spiraled. 

At the same time, Lunden was still kind to him.

Lunden detailed in her book - which will hit bookshelves on August 20 and which DailyMail.com obtained an early copy - that she met Hunter at an after-hours party at his company Rosemont Seneca's D.C. headquarters, located in the Swedish embassy building in the Georgetown area of Washington. 

She later worked at the strip club MPire - declining to spell out in what capacity - in the capital, and was paid visits by Hunter there. 

But she says in the book that their relationship was longer and more intense than initial media reports suggested,. 

It took her to Joe and Jill Biden's suburban Virginia home - where Hunter had taken up refuge after his divorce from first wife Kathleen Buhle - and also to a rental in Annapolis, and even home to Delaware, where Lunden saw Joe talking to Hunter. 

Lunden characterized her relationship with the soon-to-be first son as fun and chaotic - until it became scary and sad. 

She recounted a terrifying night in which Hunter suffered a near-overdose, collapsing in front of Lunden and her friends who were having a girls night at a ritzy hotel in Georgetown.

And she chronicled the sad end to their relationship after her pregnancy announcement.

'Over the next few days, my anxiety levels return to halfway normal. I'm still single, pregnant, and have a Dad with aggressive prostate cancer, but at least it doesn't look like the former vice president's son is going to try and kill me for getting pregnant,' Lunden wrote. 'In fact, we see each other a few times, and it's sweet and intimate, with him knowing I'm pregnant, and knowing the baby is his.' 

But then Hunter was a 'no-show' to her heartbeat ultrasound appointment.  

'I'm in a horrible place, honey, just like you are, and I don't want to hurt you. I'm so f***ed up and have so much going on ...,' Hunter told her at the time, according to the book.

While avoiding Lunden, Hunter was in contact with her friends - first her friend Kelsey. 

Lunden gave Kelsey permission to go see Hunter in Annapolis, Maryland.

'He can't call me because I've become a burden,' she wrote. 'My heart starts to break, piece by piece.' 

During their Maryland meet-up, Hunter told Kelsey that he knew he should be there for pregnant Lunden but said he was 'a f***ing loser,' his life is 's*** right now,' and he's a 'walking disappointment.' 

Kelsey told Hunter she had a recording of the baby's heartbeat.

'Kelsey doesn't reveal that I think maybe the heartbeat will jolt him into realizing he needs to step up for this child,' Lunden wrote. 

Hunter agreed to listening to the recording, according to the book. 

'She (Kelsey) turns up her phone speaker and the gentle but rapid sound of a tiny baby's heartbeat fills the room,' Lunden wrote. 'Hunter listens, staring blankly into the distance, then silently leaves the room.' 

'Worried about what might have happened to him after hearing the heartbeat, Kelsey searches the house. He's in his room, curled on the floor in the fetal position,' she continued. 

A teary-eyed Hunter then confessed: 'How am I supposed to have a child out there and be in this state? How can I have a child and not be a constant in its life? How do I clean up my mess.'

'The heartbeat got to him,' Lunden wrote. 'Suddenly it's all real, and Hunter knows it.' 

Kelsey tried giving the younger Biden a pep talk, but he walked out of the house mumbling about needing to get something - leaving Lunden's friend there by herself. 

A couple of days later Hunter resurfaced and asked Lunden to meet at a sushi restaurant in Georgetown - arriving over an hour late. 

The conversation rattled Lunden, as Hunter referenced several times that he was 'broke.' 

'I can't help but feel offended. He thinks I'm after his money? Does he honestly think of me like that? Because I got pregnant? Does he think I did this on purpose?' Lunden mused. 

He then asked the question, 'So how did this happen? Do we know?' 

'"The pregnancy?" I ask, confused. He's a smart man, surely he knows how,' she wrote. '"Yeah, I mean. I thought you were on the pill," he replied, almost questioning me.' 

She acknowledged that she was. 

'I am ... or I was, rather. But I did some research and found that an antibiotic I was taking for my skin could have messed with it,' Lunden said she told him. 

Hunter replied, 'Oh, I see. Well then it sounds like it was meant to happen,' Lunden wrote, noting that he was 'kind of laughing' in his response. 

He then started asking how she was feeling, but Lunden said the conversation felt 'different' and 'all about him.'  

'He's acting like he's broke and making financial excuses as if I am after his money because I'm pregnant,' Lunden said she later told Kelsey. 

Her friend was confused. 

'What? He seemed so heartbroken at the house when I saw him,' Lunden said Kelsey replied. 

But Lunden said she knew something was up. 

'No, he's looking for a way out. And there's something else going on. I'm not sure what, but something. He seemed sketchy. A different sketchy than the usual Hunt Sketchy,' she told her friend. 

The next day one of Lunden's other close friends, Vanessa, called her and asked to meet up at a parking deck in the Dupont Circle area of Washington. 

Names in the book were changed to protect Lunden's girlfriends. 

'It sounds like she has a problem that might distract me from the dump truck of chaos parked in my life's driveway,' Lunden recalled, agreeing to meet Vanessa.

But as Lunden arrived, 'I can see she (Vanessa) is dreading this talk for some reason. Rather than her usual smile, her head is weighed down with what looks like shame and regret.' 

'"I've got something to tell you," she says and sighs heavily. "But please don't be mad at me,"' Lunden said she was told by her friend. 

'Hunter called me last night,' Vanessa said. 

Lunden detailed her reaction as Vanessa slowly spilt out the news. 

'My palms instantly start sweating, and my body prepares for fight or flight. I sit dead still, eyes never leaving her. The pressure in the car builds. There's enough pressure to crush a nuclear submarine. Now I'm the submarine. I could explode.'

Hunter, Vanessa said, wanted to hang out. 

'He said he'd been having a rough time and just wanted someone to talk to. So I went over to his place,' the friend said. 'We hung out for awhile and drank ... We drank a lot.' 

'And ... things just kind of happened ... We had sex,' Vanessa said. 

Lunden didn't initially respond, she said. 

'We would have never done it if we had been sober! It was a mistake!' Vanessa exclaimed. 

Vanessa looked at Lunden 'scared, like I might hit her with a right hook, or completely lose it.' 

'But I don't. I just look at her. She knows I'm pregnant. She knows the baby is his. She is my friend. I don't yell or cry. I just quietly say, "It's OK, we've all done stuff we might regret,"' Lunden recalled. 

'I'm mad at her, but I'm furious at him,' she continued. 

'In that moment, I feel sorry for her, sorry for myself. We've both fallen victim to Hunter's charm,' Lunden wrote. 'She knows what she did was wrong, and quite frankly, I respect that she fessed up and apologized.'

At that moment, Hunter called Vanessa.

'I'm sitting here with Lunden,' Vanessa told him. 

'You didn't tell her, did you?' Hunter asked. 

'Yes. She knows. You're on speaker,' Vanessa replied.

Lunden said there was silence, then a 'click.' 

'We both look at each other and laugh. Typical Hunter,' she wrote. 

Hunter then started calling the soon-to-be mother of his child frantically, with Lunden letting the first six or seven calls go to voicemail. 

Vanessa had gotten out of the car and so Lunden was driving around Washington. 

She answered Hunter's call.  

'"Hey, where are you?" comes the voice of a guy who just slept with my friend while I'm carrying his child,' Lunden said. 

He then asked: 'Will you pick me up at the CVS on the corner?'  

'Is he seriously going to act like nothing happened, like I don't know he knows I know? But somehow through the anger and pain, I find the word "sure" coming out of my mouth,' Lunden recalled. 

'I pull up to the Dupont CVS. "Hey honey, do you have cash? I'm trying to get a Gatorade and my card is messing up. I can go down to the ATM, but do you have cash by chance?"' Lunden said Hunter asked. 'I should let him die of thirst, but I hand him my card.'

He then jumped in her car - Gatorade and Lunden's credit card in hand - and she drove him to the Georgetown waterfront. 

'Honey, I'm sorry, I'm such a f***up. I'm a loser. I hurt everyone around me. I'm just a f***up. It's all I am and all I'll ever be,' she said Hunter said. 

Lunden said it was 'bulls***.' 

'I know you've got your demons and you're in a horrible place right now. You've been in a horrible place since before we met, and all this time I've stood beside you. I've never judged, and quite frankly I've loved you through it,' she told the Biden. 'Now I'm in a horrible place. I'm clearly going through it alone and where the f*** are you?'

At that Lunden said she started sobbing, head in her palms. 

'It takes me a minute to realize that Hunter is hugging me, and he is crying too,' she said, remembering that he said that it's 'going to be OK.' 

She told him she had to go.  

'He steps out of the car and comes around the driver's seat, opening my door. Then dropping to his knees with [his] head against my chest and arms around my waist, he says, "I'm sorry ... I love you,"' Lunden wrote.

'"I'm sorry too. Love you." I mutter back, exhausted from the chaos and the toll it's taking on my body while I'm growing another human inside,' she said.