Now that the holidays are over, let's pay tribute to the guests. There's making yourself at home and party crashing, overstaying your welcome and snooping in the host's medicine cabinet - all that rich material for your fifteen minute write! So set your timer and get underway.
(Then for extra credit, go read Margaret Malone's terrific "People Like You" about some wonderfully awful party guests. Find it in her short story collection by the same name).