Kentucky thumb

When you're hitting it from behind and your slap her ass, to which she responds by yelling "just stick a thumb in it!"

Was banging my girlfriend last night and I have here the Kentucky thumb

by Captain Hazelwood May 20, 2021

Thumb Plumb

A thumb plumb is when there is a lump of shit left on the thumb after thumbing an arse.

Holy shit, you should have seen the size of the thumb plumb she left.

by Biggaybear April 2, 2013