So my SO hang out with a guy friend who sometimes brings around a girl friend and he knows her....I didn’t really care until I found out how she is....like she post on Instagram not even joking half naked pictures like most of them look like nudes and she even invited him to the strip club the other day but he didn’t go... he knows I don’t want him hanging out with her but he knew her before me and he says he can’t control how she is and I tried being okay with it but I’m not....am I crazy for being mad and not wanting him to hang out with a girl he knew before me....he doesn’t even consider a friend just someone he knows

Please give me your opinion I think I just need peace of mind

Ps: i know he won’t cheat on me but I just don’t want him hanging around someone like that Bc how they are and how she dresses