Skittle Swap is a game, usually played at parties where there are lots of single people, or people that just want an excuse to pash. It involves putting a Skittle in your mouth, and someone else putting a different coloured Skittle in their mouth, and you pash until you manage to swap the Skittles.

the whale tail is the shape formed when a g-string rides up high over a womans trousers