Last time I looked it was 6/1 against a white Christmas in London, but there's probably more chance of snow than of Doctor Who really getting off with his new assistant in the Christmas Day episode, despite the teasers.
I know Who does all right when it comes to the opposite sex and which woman wouldn't want to climb into a dark booth with a strange man holding a vibrating screwdriver promising the Earth (plus some other planets)?
But still. The chances are you’re either going to get your heart broken after a solitary smacker, or, if you manage to win the Doctor's two hearts, you'll end up as binary code in the TARDIS hard-drive, like former/future wife River Song.
Probably best for Jenna-Louise Coleman to play the odds and enjoy the kiss, then have her memory wiped and go home to mum, which is, after all, the traditional format for work party romances across the universe.