Mainly said because of a typo of “Shut the fuck up”. This term means that when you are fucking someone, u are shitting upwards on them.
“ayo Jason, why did u shit the fuck up on__?”
“Idk man, I’m just a somp that likes shitting upwards on people.”
“Idk man, I’m just a somp that likes shitting upwards on people.”
by simpforurmom April 10, 2021
 Get the Shit The Fuck Upmug.
Get the Shit The Fuck Upmug. An extremely unacceptable situation, especially one that involves a high degree of bad luck or unfairness.
After being crapped on by a bird for the third time in one day, Roger remarked "Man, this is some fucked up shit."
by Treebor July 22, 2007
 Get the fucked up shitmug.
Get the fucked up shitmug. To be in a bad situation which is either slowly or rapidly getting worse with no evident way out. Should you be armed with a paddle, you still, typically, have a slow long recovery 
see shitty
see shitty
by chris unger April 21, 2004
 Get the up shit creekmug.
Get the up shit creekmug. by Jessica Grimes January 7, 2005
 Get the jacked up shitmug.
Get the jacked up shitmug. by andrew September 11, 2004
 Get the fucked up shitmug.
Get the fucked up shitmug. by SeAnANAnA June 10, 2018
 Get the shit the fuck upmug.
Get the shit the fuck upmug. To be in an undesirable place, or to be in trouble. A contraction of "Up shit creek without a paddle." It can be made to define even more extreme circumstances by adding the suffix "with the repo men on the shore waiting for the boat"
by Syndustry August 28, 2005
 Get the up shit creekmug.
Get the up shit creekmug.