A Dilemma

I'm stuck. Like it says, I have a huge dilemma. Help me out here guys.
So I'm just taking a nap, minding my own business, when the doorbell rings. Not only does it ring, someone is pounding on the door. I figure it's the postman or something so I let my brother handle it.
He comes into my room. "Me-gan??" "Wha?" "There's this guy at the door, I think for you." "Who? Wha?"
I go to the door, trying to be less sleepy. It's this guy, who shall remain temporarily unnamed, who graduated a year before me and joined the military. Turns out he is home on leave for a week before he has to go back to Germany for another year and a half. He wants to go out with me tonight.
The problem is, when he told me he was leaving the country, I was happy. I sighed this huge happy happy sigh of relief because I am in no way attracted to him and he kinda freaks me out; he's almost a stalker-ish person. So I have NO desire to go out with him anywhere...to be left alone with him for fear of his getting "fresh."
So I tell him I don't know if I have to work or not (which was true) so I can't really do anything tonight. He asks for my phone number, I tell him someone at his house probably has it...(basically, no, no phone number for you, sorry dude).
Here's the dilemma, in short: Do I have a moral/patriotic obligation to do something with this guy as it is his only week in the United States before he has to go back into the service for a year or would that only encourage his creepy stalker behavior and freak me out further...?

Ack for unsuspected issues suddenly knocking on my door.