An age alarm is a spell that is put on everyone of a certain group withen a hundred mile radius. If a certain action is preformed in the presence of anyone with the spell on them the enchanted persons will point at the source, eyes flashing red, mouth open in an earsplitting scream. It will only stop when the action is unpreformed or the spell is broken. It is a variation of the age alarm Bumblemore invented.
Bumblemor put this spell on Barry to keep him from being a petting prat; so for his fifth year every time he unbuttoned, unzipped, or unbuckled in front of another magical teenager the alarm wuld be triggered. This happened twice that year; the first time was after Quiddit practice in the locker rooms. The second was in front of Bea, whom he was unaware was a witch.