A sex move where the girl inserts herself ontop the penis and begins to spin around like a basketball on a finger. The friction generated from the spin translates to the ULTIMATE PLEASURE for the dude.
Him: Babe gimme the wurly durly
Her: What's that?
Him: Spin on my dick Her: Okay. *Proceeds to spin on his dick with her vagina*
Him: *cums*
Producer: So, whatcha wanna write in this song?
Manfred Mann's Earth Band: Little early birdy gave my anus curly-wurly.
Producer: That's totally reasonable.