a piece of excrement
the reason you're still stuck in the same bad situation, like a bad haircut that won't grow out
That teacher is a piece of excrement. She gave me a D for drawing a cat on my math test.
My neighbor is a piece of excrement. He plays his guitar at 2 a. m. every day.
My ex is a piece of excrement. He still texts me about the pizza he ate in 2017.