I recently got back together with a guy I hooked up with/dated/love for a long time... we decided to move in together and things seemed to be going great. He had cheated on me the first time we were together but I wasn't scared that he was going to do it again I never had any suspision. He was being a little more lovey one day and then two days later I was hanging out with one of his best friends, she is a girl but she is bi and has told me many times that she has a crush on me. She is always flirting with me and when we drink she tries to get me to mess around with her. I was hanging out with her one night and we were talking and she said I know some things about your boyfriend that you don't. She said that he had shown her a video on his other friends phone of his ex giving him head when they were very drunk, but she said it had been the day that I was at work and his friend had work off so they drank (only two days earlyer-the day he had been more lovey) I of course freaked out but she said please don't say anything he trusts me and I don't want him to be mad but you wanted to know... then she started egging me on, you deserve better just break up with him or cheat on him live your life he is a great friend but he treats you like... etc so I was really hurt when I got home (we live together) and he knew something was up and asked eventually I asked him would you ever cheat on me? He said no you're my girlfriend I'm not going to cheat on you I love you and you need to learn to trust me. I said I was worried about him cheating and his ex he said he would stop texting her if it really bugged me. I really don't like that he talks to her... but I don't know who to believe. He sounded like he was telling the truth, I bite him sometimes so he has marks all over his chest and neck so I thought maybe a girl wouldn't do anything if they saw those... but I don't know I know his ex is still into him... its driving me crazybecause I do love him and I want to believe him but it is true once a cheater always a cheater? Or is his friend lying because she wants to get with me? I'm so confused I can't betray her trust and outright ask him who sounds more believable and is there anyway for me to find out for sure?

Consider the source, as you know she has an agenda, and it would serve her purpose to have you mad at your b/f and to break up. What are you doing hanging around with her, drinking no less??