UGH !

I feel so gross with myself right now! I've been talking to this boy on && off since last year. He makes a lot of dumb choices but he isn't a bad person. When I'm with him I'm happy and I just feel like I'm in the clouds. But, after tonight I honestly don't know how to feel about him. I went to his house to hangout and we ended up doing something, his friend knocked on his window && kinda interrupted but I didn't mind because we were finishing anyways. He had mentioned before that this friend of his was a virgin and that his friend did want to lose his virginity. I told him that the time would come and that he should let his friend handle it. The boy that I am talking to, I'll just call him C, C eventually asked me if I would do something with his friend. I was of course very uncomfortable with it and I said no. But he kept asking and asking and basically pressured me into it. I hated every second of it. After me and C's friend were done C came back into the room. He told his friend it was time for him to leave so his friend left and it was just me and him. I was being distant with him and I told him that I was probably just gonna leave. He told me how sorry he was for asking me to do that and that he would never ask me to do that again because I was his and he didn't even want me to do it but he felt bad for his friend. Me and C aren't really even dating were just talking *** you could call it. I know he talks to other girls and I try to act like I don't know but I do know. But since we arent dating I cant exactly say anything to him about it. I just feel so gross and like a disgusting person. I am supposed to hangout with C again tomorrow but I honestly don't know how I'm gonna feel after him asking me to do that. I felt like if I didn't do what he was asking he wouldn't talk to me anymore and I want him in my life even tho he isn't the best person to be in a relationship with. I feel like maybe I could change him. But if I can't im really just going to feel dumb. Please someone HELP ME!!! I don't know what to do right now.