Originally from a game called Borderlands: Pre-Sequel, this stands for when multiple sensations or actions go on at once.
ME- My butt is wet, numb, and I have a wedgie. I have a fuckin' BOOTY SALAD going on right now, hold up.
Originally from the game Borderlands: The Pre-Sequel, booty salads is when a ton of fealings an things are going on in/oon top of your butt.
PERSON- My butt is numb, I have a wedgie, this seat is wet- I have a fuckin' BOOTY SALAD going on right now.
FRIEND- Dude, tmi.