My situation: I've been having sex with my classmate over the last few weeks. However, when we are out at parties/bars, she's not really affectionate towards me at all, however, there is this one guy that has been pursuing her hard, and she'll eventually usually end up being affectionate towards him.

Example: Friday night, she got wasted and ended up hanging out with him all night, and then crashing with him at her place (she said she "slept on the couch"). However, on Saturday morning at 10am, I text her and I come over and fuck her several times (I actually then called my ex girlfriend over saturday and slept with her multiple times on saturday and sunday). Similar thing repeated this last monday with her and this guy, where she is all affectionate with him at the bar, and then sleeps over with him.

I hate the feeling of jealousy I get when I see her acting affectionate with him, however, I still have gotten to sleep with her afterwards.. How do I deal with the jealousy feelings? Drives me crazy bc I know that she still likes me enough to sleep with me often.

TL;DR: Been sleeping with this girl, she is all affectionate with another guy which makes me jealous, but she then still fucks me.