enyo asked this. truth is they never do. but when they move out of town and you get to see them about once a year (if that often), it is easier to think of them as ex.
my fwb is someone i've known for at least half of my life. we went to middle school together and were good friends. it wasn't until college that we finally hooked up one night after more than a few rounds of drinks. then we went our separate ways after college, only to find that a few years later we were both living in the same town again. consider this act 2. then she moved again for her job. but she is brought back to town occasionally and we try to get together when that happens.
so here i am with an "ex" fwb hoping that act 3 will start soon. in the meantime i am interviewing for a new fwb. any ladies living in texas want to apply?