Friends and relationships

There's this kid and I really like him but he had a girlfriend and they broke up but part of that was because he liked me and she's on my friends I don't know what to do she said I could date him if I wanted to but then she got mad and was going off on me and was telling people about it and I really don't want to lose her as a friend but I really do want to be with him we've been talking a lot and I need your guys advice on what to do