Frexing
Term for two people who are friends, but have wild uninhibited sex with no strings attached. Derived from the combination of "friends" and "sex", frexing is desirable amongst two people that are attracted to each other but share a mutual non-interest in dating. Frexing frees you from dating type obligations such as spending the night, calling the next day, sending flowers, leaving notes or faking interest when there is none. Usually initiated via late night drunken sex messaging or a made up reason to get together.