HELP???? 10 PTS BEST ANSWER??? Does he like her now and not me?

This guy and this girl had a friends with benefits relationship for a long time except that she didn't put it out. she only went to third base with him. But he seemed to like me alot but I was mad at him cause I thought he liked her and he had no clue why I was mad. So then he got all sick of my anger and start dating that fwb. He stares at me sometimes even while talking to her but he also avoids eye contact or gives me resentful looks.