The act of making out while the man is sitting, and the woman is
straddling his legs. A combinations of the terms
Straddle(n.) and
Racking(v.) Often performed on a couch or the back seat of a car.
Guy1: "Dude did you and Emma get together last night?"
Guy2: "
Oh ya dude, we were
straddle racking in the back seat of my car for half an hour!"