*you smell a dirty fart stench in the air then ask...*
"Who just totaly opened a box of butt magic in here?!"
or
"heads up..Im about to open a box of butt magic"
Said when a guy who hasn't gotten any in a while strikes out with another girl. Refers to the opening of a jar of peanut butter for the purpose of slathering said peanut butter on one's penis to provide a dog incentive to lick it.