Delaware Seniors Pull Off Epic Prank As They Sneak Into Principal’s House For A “Sleepover”: Seniors at a Delaware high school have pulled off the ultimate senior prank. The 77 students devised a plan to stay up past their bedtime, sneak into their principal's home and hideout until she woke up in the morning. The principal of St. Andrew's School in Middletown, Joy McGrath, was shocked to find out her husband was in on the prank and let them in hours earlier and other faculty helped pull off the prank too. The kids were in sleeping bags all over the house when McGrath walked out to the kitchen in the morning. They all had breakfast together before going back to their real homes.