Mash-Potatoing 

V. Mash-Potatoing is the process of slamming a semi flacid boner, a.k.a. chub, into the lips of a vagina but not actually entering the vagina.

Billy: yeah i couldnt get it in her cuz i wasnt fully hard but we were still goin at it.

Craig: she was mash-potatoing your dick?

Mash-Potatoing by craiggetshispooholelicked June 24, 2010

Mash-Potatoing 

Its the act of stuffing a condom into the lips of a vagina but not really entering.

Joe: Hey, did you actually have sex?
David: No, I was just mash-potatoing her.

Mash-Potatoing by Konoyaro Bakayaro December 7, 2015