Need some opinions

So my boyfriend is 10 years older than me and he's been married before. Divorced for 3 years, she cheated on him and that's why they got divorced. They were together for like 7 years I think. He took the whole thing very very roughly at the time but he is much better now. He doesn't talk to her anymore as she is with another man and living a few towns over, however her parents still live two minutes from my boyfriends house and he still had contact with them. He does favors for them every once in a while, and sometimes hangs out with her stepdad and rides motorcycles. It kind of makes me upset because I feel like he needs to move on from them too. I feel like he shouldn't be talking to them still. I understand they were his family at one point but that is over now. And it almost makes me feel like he stays in contact with them just incase his ex becomes single and then they can get back together. He's told me numerous times that that will never happen but I still don't understand why he has to be so nice to them and still talk to them.  Am i over reacting or should I be a little upset? I've talked to him and told him it bothered me and he said he will never get back with her and he's just being nice to her parents.