I work in a warehouse in the front office, while I don't leave my desk for lunch, (so I can answer the phones) I have a hard time eating in front of people.
This gentleman comes in, I page the respective person he needs to the front and then he stands there and stares at me. I won't eat when someone is right there because I think it's rude. Although considering that I brought the situation on myself, I have no problem waiting until the person leaves.
Have you ever been somewhere and notice someone watching you eat? Does it bother you?
On the other hand, do you enjoy watching others eat their food?