egg timer 

Used in reference to a person who you can only deal with for a short amount of time before you want to run away and/or hurt them

"She was a serious egg timer. A couple of minutes and I wanted to just punch her in the face."

egg timer by replication February 5, 2009

Egg Timer 

Someone who talks for a rather long discriminate amount of time when a conversation is started, no matter how.

Angela is an absolute egg timer. Can't just have a minute conversation with that woman.

Egg Timer by Conversation Bot v1.2 April 14, 2022