hi and bye friends
People who say hi when you come to school/work and occasionally have sexual interaction with you
I have 34 hi and bye friends
hi bye friend
A person you would say "hi" and "bye" to casually, but little more. Generally someone desirable as an acquaintance and not anything more.
From "This American Life"
From "This American Life"
After she said "no" to a date, she said we could remain hi bye friends.