I love that family. It's the first family I played with after the pack came out and has become part of my rotational play.
You don't have to break the marriage up, their relationship is rocky, she did cheat on him and has an ongoing affair, but maybe he's just looking for a friend to talk to or someone to just hang out with that isn't always upset with him since he doesn't have any friends as is.
I haven't played that save in a while but last time I played the eldest daughter had a huge fight with the mom and ran off during a thunderstorm. The dad went after her and they spent the next clear day, as it stormed for several days, exploring the world and just having some father daughter fun time. Mom hot a promotion at work and seemed a little more happier. Not sure what will happen next or where this family will go but Thomas seemed more lively once he got out and started hanging out more with others. I don't know if I'll keep them together as Thomas is very hurt from Rashidah cheating on him and is just going out and trying new things and working on just being happy with himself for now.