Um well hon. That's a hard question to answer, and ultimately only you can answer it for you. So here are some things to consider.First of all it takes two willing people to have sex otherwise if one of them is not willing It is considered rape. If you and your boyfriend live the swing lifestyle than that changes the scenario as well. Now with that said If indeed they had sex that means that unless they were both on drugs at the time than they were both willing participants in the affair. That just leaves me wondering if your sister respects you, or if she will respect your relationships in the future. I wouldn't be only placing him on the line if I were you because she had just as much a part in this ordeal as she did. I once heard a few sayings that have stuck with me my whole life and I would like to share them with you at this point. "Once a cheater, always a cheater," "You can't change a cheater," and "It's no life to live, If your living with a cheater." Hon If he has the gall to sleep with your sister while hes dating you then where would he draw the line? With some bimbo on a street corner,or would he even care? I would tend to think that he didn't consider you, or your feelings when he did this. What about STD's, or pregnancy? I wonder if he even thought about those potential issues? If I were in your shoes I wouldn't want to half to feel hurt or risk my health because he couldn't keep his fly up. I apologize in advance for what I'm about to say because you may take offense to it but I don't care how much you love him the evidence is pretty clear that he doesn't care about you hon. If you choose to stay with him ; be on the lookout for stray kids, heartaches, STD's, and the headaches that ensue with this type of relationship. Make him re-earn your trust. If you leave well good for you because you can do better. If I were in your shoes I would leave but that's just me. So make up your mind for yourself and best of luck to you in the future! If you don't mind I would like to know what you decide though and what sealed your decision. Scarletthunder
