Backseat Toker

Somebody who is not currently participating in a smoke session, but is actively trying to encourage the participants to get higher.

Person 1: "Take another hit of the bong right now."
Person 2: "Why are you telling me to smoke more? You're not even smoking."
Person 3: "Looks like Person 1 is being a backseat toker."

Backseat Adventures

when you and your s/o go to the backseat to fuck

Boy 1: “Yeah me and Stacy had some backseat adventures last night if yk what I mean”