ex-shag
Someone who you've slept with with, but your not friends anymore just an ex-fuck. While still being on good terms.
Awkward situation:
Ex-shag: How are you?
You: I'm fine
Ex-shag: Wanna hang out watching movies?
You: Sure
Ex-shag: How are you?
You: I'm fine
Ex-shag: Wanna hang out watching movies?
You: Sure