Most Helpful Guy
It's a website make available to the public, yes? If you don't care for him looking, keep it private, or off-line. And no, that hardly qualifies as "stalking".
Most Helpful Girl
No... it isn't stalker behavior. Stalking is a serious offence where someone is violating your space, privacy, and so on. He would be stalking you if he used your profile to find out where you were and actually began following you, but just looking at "snaps" you took isn't stalking or stalker like, especially if he's on your social media.