THE VICTIM: Everybody they could find, "again and again"

You may have seen fake spilled coffee in joke shops, but the Tirellas figured out a way to create the look at home. "This joke is particularly effective," Maryann says, "if you use someone's favorite cup and place it on their computer keyboard or important papers." To make your own fake spill, first choose a cup, either ceramic or disposable. (If you use a foam or paper cup, glue the lid on and open the sipping hole.) Next, mix together equal parts white glue and brown puff paint, adding more paint until the mixture is darker than the color of coffee (or, if you prefer, hot chocolate or melted chocolate ice cream) you want (it lightens in color as it dries). Pour about a tablespoon of the mixture onto waxed paper, set the tipped-over cup into it, and then pour another one to two tablespoons on and in front of the mug's lip or cup's sipping hole. Let dry (it could take up to a week), then just peel off the waxed paper.

To really twist the knife, offer your target some fake doughnuts (see Prank #7) as consolation.

THE REACTION: The distinct possibility of retaliation with fake vomit