So, everyone in this situation is in high school, and has had their share of serious and non-serious relationships. I only became close to this girl (let's call her Jane) within the past month, but she has known the other guy (let's call him Jim) for a couple years now. Jim is a friend of mine, but I wouldn't call us close friends. I really like Jane, and I thought she was really into me, too. We have a very physical relationship to the point that people that don't know us that well (and even some people that do, like Jim) think that we're in a serious relationship. We got to the point where we could be on the phone for hours on end and talk about anything. The problem is that one night when we were talking, she told me about how much she liked Jim, even though Jim flirts with a lot of different girls. I knew that they were good friends, but I thought they were just friends and nothing more. The problem is that Jim is not looking for a relationship, as he goes away for the summers and doesn't want to start anything that he would have to be away from for two and a half months. I honestly have no idea what to do anymore. Any assistance would be appreciated.
tl;dr - I really like a girl, but she likes my friend. She doesn't know I like her. He doesn't know she likes him. What should I do?