When nearing the climax of sexual activates, you turn off the lights, whip out some super glue and act like your ejaculating while pouring glue over her face and then quickly running out the door never to be seen again.
In a school project, there's always someone who does the work and someone who goes to the end of the room to get supplies like glue. Basically, you say it to someone below you, or a wench.