A Grandad - A grandad is when you knee someone in the thigh so hard it f

A grandad is when you knee someone in the thigh so hard it feels like you just kicked a brick wall.

I did a grandad to my cousin. He walked like a grandma for days.

At school, I did a grandad to my teacher. He gave me a detention.

I did a grandad to my friend. He cried like a baby.