toast hijacker

A person who after hearing a toast proceeds to add his/her own toast before drinking. This is rude and annoying. If you want to say a toast just wait for your turn.

Man1: "I would like to drink this for our children!"
(everybody but one person drinks up)
Grandma: "Yeah, and I wish that these children grow up as good and loving as we did..."
Man2: "Haha, grandma is such a toast hijacker!"