Smoking skins
The act of sex, be it manual, vaginal or anal without lubricant when lubricant is needed, making both parties raw and most likely resulting in pain.
I hit this hottie in the elevator, but we started smoking skins so I had to stop until we got some lube.
Smoke that Skin Wagon
A euphemism for fellatio. A twist of the phrase, "Skin that smoke wagon," from the movie "Tombstone."
The movie had one very steamy scene where she asked him if he wanted her to smoke that skin wagon.