When you are fed up with any situation and had enough.
I have had a butt full of dealing with this situtation.
Refers to when a full-grown man pulls his pants to the ground like a toddler while using a public urinal.
Typically at stadium or large crowded bathroom.
"That browns is going full butt in there"
Or news headline
"Bills fan goes full butt in Rival stadium restroom"
an ass filled to the brim w ranch
woah!! tracys has a butt full of ranch