Originally Posted by Dr.
Well, the ex-fiancé (if there is one) might be backstory - essentially gone before the movie gets underway. So Lois doesn’t necessarily have to dump him for Supes.
Exactly. If her relationship with her ex ended before
Superman showed up (or perhaps even if it ended for reasons Superman/Clark had nothing to do with), then it wouldn't make her look bad to hook up with/have feelings for Superman.