secret slob

An individual whose physical appearance is neat, put-together, fashionable and clean, but keeps his/her place of inhabitance extremely messy.

Someone who cares more about how they look to others than their personal hygiene/sanity/self-respect.

Negatively used as these people put much care in their physical appearance to impress others rather than take true care of themselves.

person 1: "whoa, Billy always looks so put together- he's so hot!"

person 2: "no dude, you should see his room, it's disgusting. He's a total secret slob."