asshole teeth

When you clench your but so hard it's like holding onto the seat with teeth. Mostly used while riding motorcycles or in power sports.

When the guy cut me off I held onto the seat with asshole teeth

like an asshole with teeth

A phrase describing how some peoples’ mouths are so surprisingly similar in appearance to an anus that it merits its own special phrase.

After analyzing hundreds of pictures of the Grabber in Chief, it was more than notable that his mouth looks exactly like an asshole with teeth.