IM language for Pissing Myself Laughing. Mostly it's not literally meant but it's commonly used when something strikes someone as extremely funny. Somewhat an alternative for rofl or lmao.
A British texting abbreviation. Unlike the USA who uses LMAO (laughing my ass off), the British use PMSL, which means "Pissed Myself Laughing."
Darnell: Everyone knows 6 is afraid of 7 because 7 ate 9. But why DID 7 eat 9?
Chris: I don't know.
Darnell: Because 9 has to have 3 squared meals a day! Hehe... math jokes.
Chris: HAHAHA PMSL