Also see sandbagging (verb form)
And this time please don't sandbag.
Luke: It is very easy, I shoot whomp rats back home and they are no bigger than 2 meters.
Rebel: Dude, why did you sand bag me back there?
Usually it is unintentional or by accident. it can either be a dick move or the person is completely overreacting
first coined in the robot chicken star wars
Jay- no you're not dude, aren't you a janitor?
BJ- why did you have to sandbag me in front of those girls man? i was gonna get some!
Jay-what are you talking about? what does "sandbag" even mean? they were out of your league anyway
BJ- You're a total sandbagger man...
Sam: sand-bagger, I'll still beat you in production.
Me: good luck trying to catch up to me dude.