eat a stick - When you tell a group of people you're going to die, but you

When you tell a group of people you're going to die, but you're too scared to say it in front of your mom.

I ate a stick in front of my teachers because I didn't want to get in trouble.

My brother said he was going to eat a stick if he didn't get a perfect score on his math test.

I told my crush I was going to eat a stick if he didn't ask me out.