Hmm, ok so, apparently what I was feeling is not jealousy. They are behind me RIGHT NOW having sex. And I think it's awesome. What I was confusing as jealousy, well, I couldn't eat, my heart was pounding when she was here, butterfies in my stomach.... I think I have a crush on her!
Maybe those feelings of "get off my boyfriend!" was more like "get off her it's my turn!"