Relationship

So I have a boyfriend. We've been off and on for two years. We just got back together yesterday. But there's this other guy, we've also been off and on for a year. I had sex with him like a week ago. He doesn't want a relationship with me, but he always flirts with me. I feel so much more comfortable with him though. He just uses me but he's the one I really want. I don't know if I should just stay with my boyfriend cause he actually wants me or what. Someone please help