Definitions by Monohan

Jefferson 

During vaginal intercourse, while partaking in the Doggystyle position, this event occurs when you switch to anal (extra points when done without asking your partner). Coined from the popular 70’s sitcom, essentially in more ways than one, you are “movin’ on up”.

“I tried to pull a Jefferson on Kiki the other day, bitch wasn’t havin it.”
or
Male A: “Dude, finally after 3 months of dating, Trixi let me put it in the butt.”
Male B: “Congrats mann, you pulled a Jefferson!”

Jefferson by Monohan April 19, 2007