I'm impressed with the way you approached writing your story! At first I thought, "Is he confusing some other prompt with this wewrite story?" LOL

It's really inventive and imaginative.

On the thumping down the stairs thing, I took Nathan's reason for jumping not so much that he was startled by it, but because he'd heard it so often that it's become like fingernails on a chalkboard, so the jump is more like a very animated cringe.

I picked up from the prompt that Nathan either had no father, or he wasn't around, and Nathan and his mom were the only residents at the house.