If your friend did the breaking up, its more socially acceptable to date your friends ex. Under all circumstances, it would be a nice idea to just ask your friend politely if he or she is okay with it. He or she may still have feelings for the ex, even if it happened a long time ago.

Is someone you dated an ex?

While many felt the same way, others have a looser definition of the term. Over 37 percent said they refer to someone theyve dated in the past for a certain amount of time as an ex, and 20 percent said an ex is someone theyve dated for any amount of time.