Can anyone help me and tell me what I should do?

My best friend and I like the same guy, but she dosen't like him as much as me because he is her ex but she still likes him. Well... long story to short they might go back out and she wants to know if she can. I mean I can't tell her who to go out with and who not to. But I really have a "different conection" with him than she does. Everyone is telling me that she is just going to go out with him to make me mad, because she is jelous because when he looks at me she says it's a "dreamy look" what should I do?Can anyone help me? PLease I need it badly.
Thanks

If it was her boyfriend in the past you shouldn't go out with to begin with and now that she still likes him that should be more reason not to go out with him. That's just what I think. That's like an unspoken rule between me and my friends. If one of us went out with someone no matter how long ago it was the other ones can't. It's a respect thing, you know? Anyhow, just my opinion. Hope it all works out for the best.