Thumb Cum

The art of spilling one's sexual mustard onto his thumb after a session of masturbation.

I ran out of tissues after I had a wank lastnight, I couldn't wipe off my thumb cum!!

by jackthehat June 29, 2011

Cum Thumbing

Verb

1. To merge two magazine pages together as one by means of bodily fluids.

"The fact that pages 136 & 137 were stuck together in the Hustler magazine at the sperm bank was an obvious indication that someone had been there cum thumbing it previously."

by billebllunt December 31, 2013