He's just not that into you

You have no idea how applicable that saying is for me.
NO ONE IS "JUST THAT INTO ME".
My ex-boyfriend/love of my life, for example. He apparently was hooking up with some girl for a few weeks and I found out and he said he'd stop, because we're trying to "work things out". So, this friday he is hosting an Open Mic Night at his place and invites me...AND THIS GIRL. So, when I confronted him and told him that it just made me feel weird to be around her, and that frankly it was a bit disrespectful, he said

"Well, you don't have to come then.

Fuck my life.