sanitease

Somebody who only washes their hands when there is somebody else present in the bathroom. This person would even go as far as to tear off a paper towl and pretend to dry their hands while exiting a public restroom.

Jack: "You think that guy actually washed his hands."
Brian: "Probably not. He's such a sanitease."

sanitease

A person who only washes their hands in a public bathroom when other people are present with them.

A study shows that 80% of Americans do not wash their hands when they are alone in a public bathroom. They are known as saniteases.