Case Of The Ex

This is a topic discussed by many and I think the result is usually an even split amongst those involved in the conversation. There are people who think going back to/still sleeping with an ex is cool, not  problem, that it may even be a good thing considering you already know and care about this person so you don't have to worry about being with someone new. There are others who believe that once you break up with someone you should leave them alone for good, that it's unhealthy to keep an ex around, you can't completely heal or be ready for someone better to come along if you're still stuck on your ex... Maybe you felt your ex was "the one" and you all are meant to be. Maybe you still love your ex and don't think you can ever move on without him/her. In these cases, I'd have to ask that you go over the details of the break up. Did he/she cheat? Were they abusive in any way? Did they lie to you about things that you felt were important? In my opinion, an ex should certainly stay an ex in most cases because after all you had to feel things wouldn't work out for a reason, right? That being said though, I do feel there are cases when getting back with an ex may not be such a bad idea. For instance, the break up may have been caused by one or both parties moving away. Or maybe you dated in high school, broke up, then met up again years later. Even then though, I'd still tread lightly. What do you think? Should you ever get back with an ex? Is it ever okay to have "ex-sex"? Or should an ex be an ex and stay in the past?