The Morning After...3 Fake Nails

A strange thing happened after Prom...

When our son made plans to go to Prom, he invited a group of eight classmates to our house to watch a movie after the dance. The girls showed up in Cinderella dresses, the guys in suits and ties. We'd pulled enough chairs into the TV room so they could all sit down. 
After making the required parental appearance, I announced that I'd be in the next room if they needed me for anything. I tried to stay awake, but I fell asleep. (No pumpkin-changing-to-a-magic-coach for me!)
When I woke up in the morning and went into the TV room to return chairs to their places, I saw delightfully sparkly seats (from magic dresses) and three fake fingernails lying on the carpet.
What? Who lost her nails (I assume it was a girl), and why? Envisioning a tickle attack, or a slapped face, or a girl cat fight, or the movie so intense that the girl picked her nails off, I asked my son, but he didn't know.
What do you think? What happened that made a girl lose her nails after Prom?