Is it normal to be paranoid about this?

Well, there's a girl which i fancy and i know she also fancies me (we both know how each other feels), i plan on asking her out so that's not the problem. I have a friend who is more fiendly to her than i am, we first met as a group, but i'm not that sociable in a group of people i dont really know so i didn't talk to her that much, when we're alone we talk quite a bit. But, my friend knows how we feel about each other and i can't help but feel that he likes her too and whenever he starts talking to her and hugging her i get really jealous and want to hit him, i wouldn't have a problem if he wasn't such a cunt. He's a bully, a nob head and a bad friend, but he acts differently round her, so she doesn't know what he's really like and this makes me more angry. I'm now getting really paranoid about him, and we're starting to become worse friends and the thing is, he's leaving my school at the end of the year, and going to her school for sixth form (college) and i can't help but think he's gunna try and make a move on her. Is it normal to be paranoid about this?