The couple have been rowing recently over David's wish to have a child of their own, with Kylie reluctant to sacrifice her high-flying job at the Bistro.
With actress Paula Lane remaining tight-lipped about the storyline when she spoke to Digital Spy recently, we thought we'd draw out a list of most likely contenders for the shock Christmas Day bunk up.
1. Nick Tilsley
Our main suspect, Nick's marriage to Leanne on Christmas Day can't surely go ahead. If indeed Peter's return to Weatherfield has ruined his happy ending with Leanne, he'll be furious but - more importantly - vulnerable.
Fans will have noticed some slow-burning chemistry between Kylie and Nick since the wild mum became a waitress at his Bistro. So with their love lives in tatters, who'd put a wager on the pair falling into each other's arms? Added to that, actor Ben Price recently gave a pretty strong hint that he may be the mystery man. And how could Corrie writers resist it when Nick will be committing the ultimate sin by betraying brother David?
2. Tommy Duckworth
Troubled Tommy is another strong suspect as his relationship with Tina remains in tatters after he revealed her surrogacy in the Rovers. So far Tina hasn't been forgiving in the slightest - earlier this month she chucked Tommy out when he came round to talk, and resisted his guilt trip by staying with ex David who she'd put up for the night.
Some might point out these two characters have hardly come into contact during their time in Weatherfield, but lest we point out that Kylie kissed Tommy only a fortnight ago, although she did do it in front of David as a petty act of revenge.
3. Peter Barlow
With Carla already having left him for Los Angeles, Peter's pride will suffer a second blow if arch nemesis Nick Tilsley gets his way. Should Nick and Leanne defy the odds and make it down the aisle, Peter's going to be a lonely man this Christmas, and he might be tempted to ditch Simon with the boy's grandparents Ken and Deirdre or adopted mum and possible stepfather Leanne and Nick.
4. Jason Grimshaw
Michelle Collins has made noises that Stella might not completely be over her ex Karl, so if they reunite and Jason becomes single again, Kylie would be a fool to pass up the opportunity.
5. Lewis Archer
Hear us out on this one! With Lewis currently trying to seduce Gail, could his wicked ways tempt him to try it on with a third generation of Audrey's family? As Gloria Price herself said, the gigolo sure knows how to "charm the birds from the trees".
Who will Kylie cheat on David with? Leave your verdict in the comments box below. Get the Inside Soap magazine on your iPhone or iPad