This is not to say that EVERY GUY who talks to you is a stalker. If you know them personally and hang out with them: Not a stalker (hopefully). The "stalker" title belongs to the ones that you have little or no personal contact with. (I don't want ALL guys to think "Omg. I did that one thing one time. I'm a stalker." Not true.) If it's unwelcome and seems obsessive, miiiiight be stalkery.