It's not good that your DD feels uncomfortable, but at this time you don't really have anything that's sayung he's anything more than a strange man. Maybe he has learning difficulties or social difficulties, and doesn't understand. Maybe this is a situation where you could talk DD through what to do in this situation and how to respond. She is allowed to tell him "please I feel uncomfortable when you're looking at me like that". Perhaps it's a learning experience for her.

I guess everyoneis different and it and it would be a shame for him to lose a job based on, not much. Perhaps it's the only job he has been able to get because of these social issues.

But you you have to trust your intuition as well. It's tricky