hate (someone or something) like sin
To hate someone or something very aggressively, intensely, or enthusiastically. I know you're suppose to forgive and forget, but I can't help it—I just hate him like sin for what he's done to me. Good luck getting Scotty out of bed this early—he hates mornings like sin.
hate someone or something like sin
Fig. to hate someone or something a great deal. She won't eat brussels sprouts. She hates 'em like sin. I don't want that man anywhere near me. I hate him like sin.