Most Helpful Guy
dead deal, even if you could it will not be a healthy relationship, so before you break up next time think carefully and convince your self that you will not see him again in your life.
Most Helpful Girl
Yep. But why?
Technically, if they completely moved on, they have no romantic feelings for you, so you're back to square one. At this point, if you re-evaluating your past relationship with them, and you two had a crappy relationship to begin with, you're better off finding a stranger. At least it would be brand new.
But if it's where the breakup wasn't so bad and you had some chemistry, I suppose you could try.
Most of the time, though, this would be a lost cause.