CK (casual kiss)

When making out with someone, they have little long-term meaning. It is also used when the term "hookup" is too much and "makeout" is too awkward - Used nonchalantly

It was just a CK (casual kiss); or

Person 1: Bro Last night I hung out with a girl
Person 2: No way, what happened?
Person 1: You know just a ck.