1) Phrase made popular in the song "
Baby Got Back" by Sir-Mix-A-Lot in the early/mid 90's. Overall a mad shitty song but good if you are from a small town or are black and grew up in a sterile suburb. Phrase can be used to describe a pseudo "hard"/
toughguy event where a smaller dude rolls up on a bigger one and feigns a beatdown using jerky violent motions up in his face.
2) Another common usage of this is when you eat at a shitty vegan joint (Ex: Sprouts in
South Lake Tahoe) and have to use the bathroom immediately afterwards. You drop a Kenny Loggins and leave the bathroom, only to discover you didn't really finish and have to run back in. Don't act like you don't know.
Example:
1) Yo, you see that fool that got all up in Dave's face and was like "uh!
double-up, uh! uh!", fool
straight-up served him.
2) Dave ate a sub-par
steamed egg burrito and had to uh! double-up, uh! uh! in the bathroom at the gas station down the street.