yes... i have a guy i dated in college, we still keep in contact (graduated in 09) which i think is nice, that we can be friends. but, he'd probably still think we could hook up, so i couldnt really hang out with him. i also have an ex from when i was in school out of state (back in 05) who i am still friends with, but he lives in another state. i am open to dinner or something if he comes to town.
bf trusts me, and i wouldnt have a fit if i found out he was still friends with his exes either. its not like i talk to any ex on a regular basis or are FRIENDS friends with one. so i dont think it's not kosher.
(oh, i also have an "ex" from high school, but we were never dating as far as im concerned, regardless of his feelings for me, that i have always just considered one of my closest friends. bf has met him, and we are still trying to work out our schedules so that the four of us can go out - he has a live in bm.)