Oops I think I have fallen for him...AGAIN?!?!?

So there is this guy and his name is Bobby and his sis in like my Best Friend well we dated for like 3 months and we both thought we were in love...well he cheated on me. Well you know I broke up with him. Well I got a new man and we were together for 5 months. Well we broke up...Well me and Bobby have been talking A LOT like he calls my house and I call him. He IMs me as the same with me. Well like I can't stop thinking about him. I do things for him like I did be for we got together. But I don't know if he still has feelings for me. Also I have a Man in my life and I don't want to ruin that with him. We have not been together that long only about 2 weeks...HELP?!?! I don't know what to do.