Are you three still in middle school or something? Because in the real world the girl (that is getting in the way) is called a bitch and you just ignore her and you and the other girl (the other one that is cool) have a public relationship and have lots of sex. So my opinion is fuck the bitch (as in tell her to fuck off, don't actually fuck her, as then you are fucked with jamie), and get with jamie, no more sneaky sneaky bullshit.