A white boy who doesn't know how to dance and therefore reverts to excessive grinding with his dance partner. Hand waving is optional.
Dude, you were all up in that chick's business, you fucking grindstone.
Object of toil. The burden each man carries when he is taking care of his business.
I keep my head to the grindstone during the day to pay for my lady's shoes and the kids' piano lessons.
But at night I leave that grindstone alone, let the kids practice their lessons in their rooms and let my lady, booty to the bed, lift her heels to show me the fruits of my labor.