thumbing a softie 

to use one's thumb or finger in an attempt to prop up one's soft, flacid, floppy penis during intercourse

Robbie Houstoun, AKA 'Floppy Robby' is thumbing a softie, but isnae fooling anybody

thumbing a softie by macfear August 23, 2014

thumbing in a softie

The term given to pushing a flaccid penis into the vagina.

Drunk dude: Im too pissed, its never gonna work
Female: Cmon work with it otherwise ill fuck your friends
Drunk dude: Well alright ill try thumbing in a softie.

thumbing in a softie by Jared Ellis January 18, 2008