A fork of Rural Dictionary
The sound/look of when a man is fully erect and his partner pulls like the man's underwear/boxers straight down to bend his dick downwards and when the underwear/boxers go past the tip, it immediately springs upwards and wobble bounces slightly as a Sproing!
Dude, I was about to get head when she yanked my boxers down and I nearly took out an eye when I sproinged upwards