I hope you can help. I’m searching for a book about unrequited love.
He’s married or maybe just in a serious relationship and they have a kid together.
Something happens and he gets drunk and has sex with the heroine and doesn’t remember the next day. Then his significant other tells him she’s pregnant again and he goes back to her.
Some time later he finds out that the second baby isn’t his. They have two little girls and I think at some point he was a professional athlete.