WANTED: Advice

While I was on vacation, one of the guys from our I.T. department sent me an email. Someone had sent the I.T. department an email asking for my email address. One of them forwarded me the email and asked if I knew who this guy was and if they should give him my email so I looked up his name in our system (thinking I had helped him with something before I left and he had questions about it or something) -- nada. IT knew I was on vacation and wouldn't do anything about it until I got back. (Bless them.) I mentioned it to one of my co-workers and she said that someone had called a couple times asking for me but didn't want to leave a name or a message. Weird much?

Yesterday I stayed a couple minutes after work chatting with another co-worker while she was finishing up her stuff, naturally we walked out to the parking lot together. As we are heading toward the door we see someone walk to our front door right as we are opening it. A guy was walking past and "casually" wanted to look through the window. As we are walking out he smiles and says, "Oh hey Andrea," (like we were friends) I kinda half smile and he proceeds to stick out his hand to shake mine and says, "I'm Andrew." (NOW, at this point I haven't connected the name Andrew from the email to this Andrew that is I am shaking hands with.) After he introduces himself to me and continues to walk with my co-worker and myself to the lobby, he turns to her and introduces himself as well. His body language was strongly suggesting "introduce yourself to the other girl too so you don't look like a psycho freak." (mm..too late.) With a puzzled look on my face I ask him, "...Were you looking for something?" He said that he wasn't, that he was just waiting for someone. I responded saying something like, "Oh ok. Have a good night." My co-worker and I silently walked out the door, and once we were outside, let out a sigh of relief and both made the comment of how weird that was.

Today, at 4:12, I get an email. An email from an Andrew. Saying "Hey Andrea, How's it going? I got your email from the IT department (which, might I add, is a lie because I checked with them and they did NOT give it to him). I didn't know what your hour were down at the credit union. Would you like to go to lunch? Im going to Apollo Burger this Friday. Let me know. Andrew"

Hm.....would anyone else be c.r.e.e.p.e.d out by this??? Cuz I most certainly am.  He's not a member of my financial institution but he does work for the company that my financial institution is housed in. If it were my personal email I wouldn't respond but since it is my work email I feel obligated to.

What am I supposed to do?