When you squirt mustard (peanut butter works too) on your erect dick (flaccid works too) and come down on the fore head or cheek of your passed out brosky. Before, during, and after the event, you and your awake broskies must chant "Mustard DICK slap! Mustard DICK slap!" and record it with a phone or some shit like that.
Everybody: "Mustard DICK slap, Mustard DICK slap!"
(SLAP)
Everybody: "Mustard DICK slap!"
Victim: "What the FUCK!!!"
Everybody: "Mustard DICK slap, Mustard DICK slap..."
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi