He may not be doing this deliberately. Perhaps he has a tab on his web browser open, with your profile on it and it registers that he has been looking at your profile, when he hasn't. Maybe he's checking to see if you're still online and looking for another date. Who knows? Either way, it doesn't matter. He was mature enough to tell you that he didn't see a future for the two of you, now you have to be mature and let him go. If it bothers you that he is looking at your profile, then use the dating site's security options to block him.