The art of placing one's thumb into another party's bum while having intercourse "doggy style", with intention to rev up the current situation. Much like a dirt bike, the more you hit the throttle the more it should get things moving. This is much different than stinky pinky and is generally more acceptable than other phalanges going into the bum. And it's also easier to clean mud thumb than mud helmet.
Hey Adam, last night I was hittin' it from behind and she really didn't seem that into it, so I decided I would try droppin' the throttle to spice things up. She loved it just like the last women!
by Witti G June 25, 2014