I agree with you, Also, I think when a girlfriend fiance sim gets pregnent and there was no woohoo between the couple, there should be some consequence. He should know that she cheated on him. Also if the baby is a different race why is that not a problem to the male sim? At least a "Hey how can that child be mine?" or "suspicious" moodlet or something.
In the 'family tree' panel it will show the wife with a baby from a different male sim, he knows it is not his biological child , but everything is hunky dory with the couple. Where does he think this baby has come from anyway?
Smarter Sims, hah I was hoping Love struck would've addressed this issue but I guess that would be to much to ask.