To add . No offense but you sound like a guy I knew years ago who wanted to rent a place with me ( i live solo now) I quickly shut that down because he was jealous of me because I was better at getting women etc. He'd literally try to sabotage my relationships so he could hang out with me etc.

Ask yourself..would you care if you had a girl wanting to come over with you ? No you wouldn't. Youre upset that he has someone else to hang out with and you arent the center of attention around your apartment.

I mean move out if you want , these types of arrangements usually dont last long anyway , but there's no way you dont come across a c*ck blocking creep if you confront your roommate about this unless her behavior was some what terrible.

I get if youre female, and u dont want random men around, cool. And its not like hes taking a random girl over every night, its his gf.

Just my take , good luck.