I mean, it sucks to realise you don't have close relationship with someone you want to have that with, and other people have closer ones. It's on some level common and normal to feel like the problem is those relationships overstepping, if you feel entitled to be the closest circle. But that's not going to get you what you want. What would in this case? You say your kid is marrying someone you don't know very well, you're jealous of her socialising with your kid's other parent's family...have you tried to get to know her? Have you tried to know your son very much? Maybe start there.