legslapping 

To slap your legs and make it jiggle.

JACOB, STOP LEGSLAPPING. YOUR LEGS ARE GOING TO TURN RED.

legslapping by Fred's furry ass January 19, 2017

Legtapping 

An awful attempt to flirt with a girl, usually considered awkward by all spectators

Aw, John is legtapping so badly I think I'm gonna puke.

Legtapping by david622 November 5, 2008