My dh and I are friends with almost all of our exes, save for his ex-wife (she screwed his brother and left him with two kids, so can't really blame him there). Friends tell us that we're crazy for talking to exes and always talk about how we can't trust each other for doing that? One of my gfs told me "better lock him up because he's gonna go back and hit what he's already had before." Classy, I know, lol.
Anyway, are you friends with any of your exes? Do you think it's weird that we are friends with so many of ours?