Usually specific to soldiers, or other people who are forced to live in close proximity for long periods of time without either sexual activity or privacy, a whackatorium is a small shack made out of blankets, ponchos or poncho liners that is erected so that the builder can masturbate in relative peace. It is often explained away as a means to block light, or provide privacy to change, despite being erected almost exclusively around one's sleeping quarters.
syn: jack shack
God, we've only been here a week and Gale's alreadybuilt himself a whackatorium!
A sex game. This game has two players. Player one bends over and spreads there ass cheeks. Player two stands behind them with a hard dick. Player on then pushes out a turd and tries to suck it back inside there anus before player two hits it with the head of there penis. When the penis makes contact with the turd, player two then uses his shitty penis to write the score on player ones back in Roman numerals.