The term, "Keeping it Clean" refers to the act of having sexual relations ("doing the nasty" or "boinking") in a bathroom stall. It is typically done in a public restroom, a movie theater, mall, liquor store, but mostly at high schools.
"Dude, that hot girl was totally into me. We were Keeping it Clean in the bathroom stall while no one was in there."
by crediblesource May 25, 2012