out-Herod Herod
To deliberately outdo someone in cruelty, idiocy or something else so as to get back at them.
I didn't care what anyone else thought of his wedding speech in the marquee; one way or another, unaccustomed to public speaking as he was, it drove me to the edge of sanity. So in the end I just got up there when he was finished and for the next three hours, until the Security bundled me out the flap, I decided to out-Herod Herod and went for it.