Just do it, get it over with! Try to do it with ether no one else around, then I doubt everyone, if anyone else will find out! And even if they do, at least you had the guts to be rejected. A lot of people don't take the chance because they don't want the chance to be rejected! (Thats from the books I've read and like 10 people I've talked to)
But I said just go for it, sounds like shes in to you. You can't go anywhere with-out take some kinda risk.