Alright, so first things first, this story isn't completely up to Mibba rules of formatting. Every paragraph needs to be double spaced, and you seem to have some double spaced and some together. Also, this is just a matter of opinion, but I would put more paragraph breaks in in the middle chunk, because it seems to get a bit thick in there.
I thought it was beautifully written. Your word choice was impeccable! The imagery was very, very good. I could picture that scene of your character sitting on the hillside so well. Absolutely amazing there.
I don't know if this is just something with me, but I don't generally think the use of ellipses looks good outside of dialogue. I doubt that that's a real grammar rule, but I just think it makes it look less professional. Again, just me, probably.
It's kind of funny, when I started reading, I was thinking, "Wow. He's really obsessed. Like, serial killer obsessed. I bet he kills her." I didn't really believe it would happen though! XD
Your ending was perfect, I thought. Just the way you went from having a lot of detail with his thoughts, to moving not only outside of him, but outside of the scene to the neighbors was a great idea.
In short, I loved the story, but if I was you, I would work on the formatting a bit. Make it look as pretty as it is. :D