Definitions by PHAT Betty

tub thumpin 

Engaging in sexual activity (usually intercourse) while under water . . . most commonly in a hot tub or bath tub but can refer to pools, lakes, ponds etc..

Joe and I went for a skinny dip at the cottage and it was such a turn on we ended up tub thumpin'.

tub thumpin by PHAT Betty November 28, 2007