The dance you do while cumming and standing up with your pants around your knees. Usually while receiving a BJ or Jacking it into a toilet. The action is an awkward tottering from left to right, resembling the R2-D2 dance when everyone receives medals at the end of Star Wars.

Also refers to a specifically awesome happy dance that is the same action
I couldn't believe I won, I was so happy I did the R2-D2 dance.

She was so hot, I did the R2-D2 Dance in the bathroom a few minutes ago.
by Luke Amadeus Skywalker December 27, 2011