Sittin up fat 

When someone has provided a luxurious lifestyle for another

KT: I saw her baby daddy at the East Side Motel spittin game on some ho. Ain't his boo Pookie?

Big Ames: No, he don't stay with her no mo. Before she blew all his scrill, she was iced out, rollin a Mercedes, and livin at his sick crib. She didn't even have no job. He had her sittin up fat.

Sittin up fat by Amy Clemmons & Katie Foster December 14, 2008

settin up shop

to be the first,to allow other people into the same field

yo lazy ass aint do shit, while im out settin up shop

settin up shop by Adum May 19, 2006

sitting up 

In jail/locked up. Used as slang to reference experiences of being locked in a cell with nothing to do but sit up and think.

“Judge gave him 20 now he’s sitting up, sad story man”

“Most the niggas I grew up with are either sitting up or gone” - A boogie

sitting up by Black mass January 13, 2021

sitting around with your thumb up your ass 

Doing nothing.

What have you been doing all day? Sitting around with your thumb up your ass?

sitting around with your thumb up your ass by brando56894 November 20, 2013