Mary Fowler and Nathan Cleary have a touching airport farewell - but one detail will shock the footy stars' fans

Nathan Cleary has been photographed farewelling girlfriend Mary Fowler in touching scenes at Sydney Airport - with the snaps revealing a telling detail about Aussie sport's hottest couple.

The Penrith NRL halfback and Matildas star said a tender farewell as she flew out for Australia's match against China in Adelaide on Friday night.

They were smiling and holding hands as Cleary wheeled her luggage for his partner before she checked in, then posed as she took some photos with a disposable camera.

The stars also posed for some fans who spotted them, then shared an embrace before the 21-year-old flew out to join her Matildas teammates. 

Both were dressed very casually in tracksuit tops - but a closer inspection revealed there's a huge difference in their wardrobe choices.

Fowler went with a simple Adidas piece worth around $90 in Australia, but Cleary chose a Rhude beach club printed hoodie that's worth up to $1175 down under.

The pair have been an item since late last year, with Daily Mail Australia exclusively revealing their romance in photos of Fowler resting her head on the footballer's shirtless chest in a Perth park ahead of another Matildas match.

Late last week they were spotted at a cafe in the southern Sydney beachside suburb of Cronulla as Cleary remains out of footy with a troublesome hamstring injury.

Fowler, meanwhile, is right in the thick of the Australian side's preparation for a run at a gold medal at the Paris Olympics in July, with her goal-scoring ability taking on added importance due to the absence of injured striker Sam Kerr. 

They first attracted attention as a possible couple when they were spotted together on two occasions following the Women's World Cup in Australia last year.

Their first public appearance back in August last year included a relaxed stroll along the Nepean River in Penrith, where the 25-year-old NRL sensation and the Matildas striker were observed enjoying each other's company.

Additionally, they were seen sharing ice cream after participating in a promotional event hosted by Adidas, a brand endorsed by both athletes.

The couple officially unveiled their romance in Perth in October, confirming the suspicions raised by their earlier sightings.

Cleary finally went Instagram official with Fowler in January this year when he shared a photo of them sitting on an Aussie beach together, along with the caption 'that's life'.

He also added an ice cream emoji, a pointed reference to the first hint that the pair were an item back in August.

Cleary's camp initially denied that the pair were dating, saying it was 'just ice cream' and nothing more.

The power couple enjoyed time together over the Christmas break with Fowler afforded a few weeks off for over the Women's Super League's winter break.

The pair were reunited at Sydney Airport late last December, having not seen each other since November 2, and were almost inseparable until her return to England. 

Fowler spent a couple of days over Christmas away from Cleary, which she spent with family in Cairns.

Both athletes are said to be very private when it comes to their relationships, but Cleary admitted that the intense spotlight on his personal life is something he didn't expect.

'Obviously it's different from when I was young coming into first grade and people are dissecting my game. I hadn't had that before,' he said.