Since the older Sophie (Kim Cattrall) said she met her son's father on the night of the premiere episode, we couldn't rule out Charlie (Tom Ainsley) as a contender. Still, among Sophie's crew of friends, Charlie was always the least likely to be the father.
Charlie spent season one dating Sophie's best friend, Valentina (Francia Raisa), and even though they split, dating her friend's ex would be a pretty low blow for Sophie. Charlie and Valentina explicitly split because he doesn't want kids, and she does, so this turn of events would be majorly devastating for all involved. Plus, he's also in the Valentine's Day episode.
And then there's the season two finale. In the last moments of the episode, Sophie reveals that Charlie and Valentina did get back together and had a baby of their own. We can definitively say that Charlie is not the father.
