Depends on the relationship, one of my ex's broke up with me "because she could not do this anymore", i was really gutted about it, but i kept talking to her, she went out with various guys all who turned out to be no good for her as she admitted to me, but would keep doing it, all along and inbetween the relationships texting me random messages saying she was thinking about me and leading me on only to shoot me down in flames when i suggested we do something together one day.
The other day i deleted her off my phone, msn and threw away anything to do with her, simply because i realised how much i was letting it get to me, and stopping me making new relationships, because every other week i was getting empty promises off her.