nail in the wall
A guy who’s so heartless he could freeze a dead rat and call it a day. Girls get the ‘hole in the wall’ because they’re just as bad but with more drama.
My uncle is a total nail in the wall. He’d step on a puppy and laugh.
She broke up with him and he didn’t even flinch. Classic nail in the wall.
My teacher said I was a nail in the wall. I didn’t even know that was a thing.