To make a shot during basket ball which in this case would be a slam dunk before the other team can react. Also what Sans says at the end of Genocide in Undertale.
Timmy went for the basket and afterward shouted "Get Dunked On!"
Sans tricked you and said "Get Dunked On!" Not again you thought.
Getting Dunked On is a form of being destroyed, to the point of death. Usually this is when you get backstabbed. This also usually performed by a skeleton named sans. E.g:
Frisk: I'm sorry I killed ur brother or something
Sans: k. also, get dunked on *stabs in face*
v. During the act of spooning, the individual in the position of the "small spoon" farts on the "big spoon's" genital area, thereby dusting the big spoon with love.
Last night my girlfriend love dusted the shit out of me. Her love was so strong I had to leave the room.
Dude that girl I took home last night love dusted me.