Not really, no. Mike fucks his girlfriend no matter how much Lena might wish he doesn't. Cindy also likely fucks Wade, and Emma is into casual hookups and has a few people to go-to if she wants to scratch the itch. For all we know guys like Robert and Mark also fuck other girls outside of what's presented in the game.But during the game, they can only fuck with our choices.
Honestly, expecting Ivy to abstain from sex completely for literally months the game takes place, is completely unrealistic given what we're shown of her attitude towards sex.