It's not as bad as stalking but it's kind of harassment. I've had some guy keep messaging me while professing their love for me while they have a gf. omg, he was obsessed with me. It was a year and then all of a sudden he emailed me telling he has always loved me and he liked sex with me. I blocked him on email and fb. This behaviour does scare me if they are really obsessed. I find it scary too. No more from him, I'm glad he's out of my life.