So you don't have attractive or unattractive female friends. You're trying to fuck the attractive ones (thereby making them objects of sexual frustration), and don't want to be friends with the unattractive ones?

Look I'm not friends with all of my ex's, but I'd be a shame to not talk to someone because we happened to have sex. The only reason not to be friends is if that friendship hurts, basically if you feel the pain of the "loss"