I'm sorry but when did it become okay to date friends of your ex???

I just don't understand that one.
I could never and would never date anyone that was or is a friend of one of my ex's ESPECIALLY if we were intimate because they don't need to be sitting back comparing notes. That's just a very uncomfortable situation to me.
Would you care if your ex dated one of your friends? I can't say I've never been attracted to an ex's friend but I just can't cross that line.
