Backsex
the act of wen a guy is sitting on the ground, bed, or couch with his legs spread and his girfriend or otherwise sits leaning against him sitting just so her back lays right in the crook of his crotch. this usualy causes the guy 2 develop a boner.
I saw kyle poking his dick into julie's back! haha! they where having some hot backsex!!!
Jonas Backsex
Term used to describe when any of the Jonas Brothers are touching backs while performing. Usually between Kevin and Joe, whilst Kevin plays guitar and Joe sings. Orgasmic.
I would give anything to be in the middle of some luscious Jonas Backsex.