Interpretive Dunce 

This person has no skill at dancing, yet will try to auto-choreograph their unholy movements to the lyrics of the song being played, often with a delay as they can't remember the lyrics, and have to come up with something on the fly as they hear it.

"What the hell is John doing out on the floor?"

"Sounds like 'We Are The Champions' came on, and he's an interpretive dunce..."

Interpretive Dunce by Ambad June 24, 2013

interpretive dance 

A cross between Twister and dry humping; often performed by stoned hippies to the sound of hand-drumming and/or didgeridoo.

"Check out those guys doing interpretive dance."
"um... that one's a chick."
"... but her armpi-"
"yeah, I know."

interpretive dance by Rock Deputy September 24, 2005