"Dating your friend's ex is like asking him for the last slice of his pizza. You know he's already done and probably hates himself by now, but it's still his to eat. There's also a voice in your head saying 'pizza!'"
"I really don't see the issue with it. It all depends on how in-sync you both are. When the feelings are real, you can't fight it. How you handle it is more important!"
"Personal histories get in the way and everything gets complicated. It's a bit of a grey area. Perhaps if the couple is in another city or something, it may work."