We were out at a restaurant and saw a waiter approaching with food.

Dad: Is that ours - ah, no, it's theirs.

Me: *slides a butter knife across the table* Do what you need to do.

Dad: *takes the knife and hides it under the table, tracking the waiter with his eyes*

Mom: ISABEL

Dad: *takes the blade of his knife between two fingers like he's going to throw it*