That’s one thing about the game I don’t particularly like. Where the partner doesn’t react to children that aren’t theirs or looks like them. ?
I am not sure if they are more faithful to the partner if they have more than one kid. Once I kept a husband and boyfriend in the house with one of my sims. She was cheating on him autonomously and preferred the boyfriend over the husband almost. He and the husband had three children together. So I’m not really sure but it seems they have more of a preference for one or the other. If that makes sense haha ?