Sims won't perform romantic interactions

I have a couple that were together since teenagers, and ever since they both aged up, they will not perform romantic interactions with each other. Their relationship is maxed out, but every time I try, they jump apart of the entire conversation just ends. I've read it is a problem with the Lovestruck pack, but I can't find any way around the error. I have no CC mods or anything like that. I've tried moving one in with the  other and then back out, but nothing works. I put a lot into this game of the sims, so I would hate to have to start all over with them.