The optical illusion created by some jeans and pants that gives the appearance that you have a boner when in reality you don't. AKA pitching a tent
Those blue jeans gave me a killer 5 inch bunch up
When something goes wrong or your put in a horrible situation.
"You just pissed in my ear! Thats bunched up like a mini skirt!"
When a girls vagina or any given orifice is crammed together onto itself usually due to a dry penis or any given larger object.
I was at Sallys last night. She got bunched up!