omfnfs 

Something you say when you are in shock, or can’t believe something that is funny

“my cow gave birth to a goat named Sylvia”
“OMFNFS”

omfnfs by hippocritamus May 13, 2018

OMFFSM 

Used by Pastafarians and Spagnostics;

Oh My Fucking Flying Spaghetti Monster

Used like omg or omfg, but undogmatically broadminded... in marinara.

OMFFSM!!! That's a gnarly lil' eyepatch yea has there matey!

OMFFSM by Johnny Ringo aka Jeru Zalem March 14, 2009