Thumb Bumm

When you put your thumb in someone’s ass while walking by... Like a Wet Willy but with your thumb in their butthole.

Yo.. I just did a Thumb Bumm drive by to this rando girl at the bar.

by BEANERSCHNITZEL June 6, 2018

Thumb-Bummin

When one is bored and lonely so one masturbates with a thumb wedged knuckle-deep into one's own anus.

I told them I fell asleep early because I didn't want them to know I spent all night Thumb-Bummin.

by J. M. Fuhqueny November 5, 2023

Thumb Bummer

A retarded homosexual who scours the Urban dictionary giving thumbs down to everyword just for the hell of it. They also enjoy shoving their thumbs down into their underpants and giving their anus a good poke.

"Watch out for this one." "He's a dirty little thumb bummer."

by Mr Lizard August 25, 2004