Referring to the exchanging of bodily fluids between two guys through the course of anal sex.
One may say this in a joking way to ones chums to gain a chance of laughter, but has really got, what the youth of today call "issues" and should stop being so "batty"
Mike says to Patric
"mate forget about going to The Hart, lets go to that gay bar - The Birdcage. After all, one up the bum no harm done." This is when Patric would probably knock the shit out of Mike, grab a beer and go to The Hart.
by Mike June 6, 2003
Get the one up the bum, no harm done mug.
When you're outside having sex and you're ass is facing the wind and the wind blows up your arse a bit. Like if you part your arse a bit it'll get wind up it.
Y'know when you're at the park and you get wind up your bum crack just at the wrong time and your whole body shrivels up into a little raisin and you pull this face...
by _Undefined February 9, 2019
Get the wind up your bum crack mug.
1) The art of mucking around and generally getting nothing done.
2) Description relevant to the most common state of teenagers when they leave school
Since Crissy left school, all she's done is sit around with her thumb up her bum and her mind in neutral
by jimsweirdnakedindianfriend December 1, 2009
Get the sit around with her thumb up her bum and her mind in neutral mug.
To be sexually frustrated to such desperation that you might venture into the countryside and do the aforementioned act.
"I'm so horny, I could dig up a badger and bum it!"
by Jaffy23 October 16, 2006
Get the dig up a badger and bum it mug.
When you know you have a massive shit brewing and its going to be huge!
"I've gotta go to toilet I've an egg up my bum!"
by Arsebiscuits82 April 18, 2018
Get the egg up my bum mug.