The random item one buys when purchasing an embarassing item, such as condoms or gas reliever in order to offset the awkwardness one feels toward the cashier.
When buying a pack of gum so you don't walk up to the register only holding gas-x, the gum is your item of shame
What happens in any Mario Kart game when you get hit with a bunch of red and green shells, obstacles, and blue shells at the same time bringing you from 1st to 8th/12th. Brings the anger out of you instantly.