When a male inserts his penis AND testicles into the urethra of another male, causing the receiving male to have a "fat sack".
Guy 1: Honey,I want myself in you, but I'm tired of just anal
Guy 2:Okay, let's give me the fat sack.
Guy 2:Okay, let's give me the fat sack.
by Ballsballsballssack February 22, 2010
by Lucyyfur June 09, 2005
by Lade1020 March 02, 2008
by Marvinhanovver August 21, 2009
'i have fat sacks under my biceps'
by Georgiona November 02, 2007
by Daddy Fat Sacks June 05, 2003
by beanerinotaco34 January 29, 2009