The The 11th finger that comes out of a girl's bum to enter a man's bum while they are having sex.
The sex was pretty bland until her bum finger crept out.
by Sebastian Ro-Fo December 7, 2013
The expession used to describe one's fingers after one has satisfied their habit of picking their anal passage. The individual associated with this habit is Sir Steven of Stechford. Rumour has it, the bum fingers of the master of this art, can be caught by scent from over 200 miles away.
"Steve, get your bum fingers away from me."

"Steven, I can smell your bum fingers"

"Where is Steven?"
"Probably sitting at home with his fingers up his bum"
by Jonathon Locke August 15, 2008
Scratching/stroking ones ass crack, then gently brushing finger/s under victims nose, so they catch a horrific scent...WARNING: It is possible to become obsessed with sniffing your own fingers
"Last night, outside reflex, Robbie bum fingered Vicki and she was shocked"
"Vicki scratched her ass, and sniffed her own fingers and couldn't stop....'what an odd, enchanting scent' she thought"
by haha47 January 29, 2009
Inserting the finger into anothers bum
Dalton, Fingered Zhanaes bum cause she had her period. and he found a way around it,

Zhanae enjoys bum fingering
by Doodleface July 4, 2009
The Fingering of somebody's ass crack to maximize pleasure. Can results in nails being snapped off and internal bleeding. Bum Finger ussually takes place after a good bout of fart eating leap frog which creates of lots of sexual energy and vibes.
"Catch my fart in your mouth Amelie then jump over me and fart in mouth, it really makes me horny!"

"OK! But can we do Bum Finger afterwards because i've been priming my fingers all weak by sticking them in my own shit"
by CaptainMorgan'sMum September 6, 2011
This phrase can be used to put emphasis on how giddy a friend, colleague or a familiar is.

It is usually used when said people have a sense of achievement or acquired something cheaper.

It can also refer to masturbating your anus with one of your fingers because you're too ugly to get laid.
Man 1: " I got a 2 for 1 deal on these sandwiches!"

Man 2: *makes masturbation gesture* "Finger bum wank sandwich deal!!! You're really saving those pennies!"

Or

Man 1: "Hey I got her number!"

Man 2: "Finger bum wank! She's only the village bike Mr sloppy seconds!"
by FessSquad June 1, 2022
The act of kissing ones partner standing face on and flanking a sneaky finger into the anus to cause surprise
Michael was under the impression dale just wanted a kiss. Little did he know Reza was setting him up, face on for a finger bum flank
by DoctorZig March 4, 2016