My boyfriend is friends with a female he's known for a long time. They've always been friends and he says she's like a sister to him. I've hung out with her a few times, but she seemed to have a problem with me being there. Whenever we hang out she seems to get jealous or seems uncomfortable that he's with me and seems bothered when we're affectionate with each other. I tried to be friendly with her but I have a feeling she doesn't like me. My boyfriend knows I've had some issues with her but is happy that I made the effort to get along with her. I don't know if he's aware of how she feels about me, but he says she thinks I'm really cool. I don't really believe it and I don't believe that she ever wanted me to hang out with him, his friends and her. I think he's aware of her jealousy but chooses not to say anything about it to me maybe out of fear it will upset me. I don't know why if he suspects that she doesn't like me or is jealous he won't confront her about it. Or maybe he has, but doesn't want me to know she wants more with him. Also I saw a text she wrote to him a while ago saying that she thinks he shouldn't be in a relationship and should be single and have fun. Obviously he didn't listen to her cause we are still together and are getting serious but it upsets me a little that she doesn't support our relationship and also that he's still friends with her despite kind of knowing how she feels about our relationship.