The problem is so often in popular media/books/etc it's played out that the girl says she's not interested, but deep down inside, she really is. And if the guy is persistent, it's cute and flattering. So many guys - "nice" guys - think if they spend time with you, support you, etc, they're owed a relationship. Every action and favor isn't just a "of course I'll do that, we're friends", it's payment towards a future relationship. When the girl doesn't pay out because she's not looking for anything beyond friendship, she's treated like she reneged on a contract even if she made that clear from the beginning. Watch, the minute Jenni starts getting firm with him and trying to break things off, he will go on the offensive - what a jerk she is, how he's a nice guy and has done so much for her, how she used him, etc. All things that are false, but she didn't give him what she wanted so she has to be the bad guy.
Sorry, obviously a pet peeve.
This guy is a creep. The minute a guy tells me that I "don't know what I want" I run. How demeaning.