Makeout-a-thon
When a girl and guy makeout excessively. Almost a rude form of showing affection, because there usually is a "i don't give a shit about you" attitude towards other people in the area.
Gary - "Holy shit! Mark and Amy have been having a Makeout-a-thon since the movie started."
Henry - "Surface, Mark, surface!"
Henry - "Surface, Mark, surface!"