Is he truly over his ex?

Is he really over her? We've been dating for three months. We started a month after his previous relationship ended (he wasn't clear about who ended it), this relationship was ten months long and she was his first love. She cheated multiple times and lied constantly (he is not my only source on this). I told him it was okay to talk about it, because I figured the pain of the betrayal was hurting so, as his girlfriend, I wanted to be there for him. But she came up more than I could handle. I tried to show him my favorite song, but he said she loved it to so it was a painful memory. He hates my favorite genre of music because she used to listen to it with him all the time. He says Im the only girl who's ever really cared about him. He says Im a breath if fresh air and has implied that he loves me but doesn't want to say it first. He's fun and makes me laugh but Im losing it with jealousy of this girl. She's very pretty, which just adds to the insecurity. He admitted to me the other day that when classes started up again (they attend the same college) he would try to talk to her, "not to flirt, just to try to be friends." He'd been telling me for months that he hates her. That he doesn't want anything to do with her. Yet while he was saying that he was trying to befriend her. And thats terrifying, because I know that plan, to become friends with someone you used to have a thing with. Then maybe she/he'll realize she/he still wants you, and maybe you too will fall for each other again. I do not know that thats what it is. But I need someone to tell me what they've learned about situations like this, both negatives and positives.