Answer:
He has a paraphilia known as fetichism.
Step-by-step explanation:
Fetichism refers to the sexual excitement a certain object, part of the body or element provides to an individual. It tends to awaken the individual's sexual drive and get him/her excited.
In this case, it can be concluded that Sam has a foot fetish, which means that feet drive and can awaken him in a sexual way. He views the work at a shoe store as the ideal job but is fired since his interaction with customers might make them unconformable when he gets close or at the sight of their feet.