A male who expects a female to accept his romantic advances simply because he is "nice," and is angered when she does not.
Possible causes for this phenomenon:
1.) He views romance as a prize he is
entitled to, like his allowance, as long as he behaves himself.
2.) He thinks all women are the same dainty, smiling, flower-picking
Disney princess, who want nothing more in a man than giant smiles, polite chit-chat, poetry readings, and doors held opened for them. He does not understand that women are individuals.
3.) He has a
mental disability that encourages girls to put on a super-nice act around him, as they would around a child. He mistakes this for their real
personality, and thinks they are really getting to know each other and clicking, when...no. (This one's pretty tragic, and no one's fault, really.)
4.) He's a really bad actor, so even girls who DO want a "nice,
sensitive guy" can see right through his crap.
5.) He is a genuinely nice guy, but only goes for hot girls he has nothing in common with...while complaining that girls always go for the "wrong" guy.
6.) A closeted homosexual or transsexual, who has discovered how conveniently the "nice guy" motif can cover up his secret. ("I'm just not a man's man!") This can leave a bad impression on the girl, after she learns the truth. She may become so paranoid, that if the next guy she dates cheats on her with another woman, she may break into a joyful jig, exclaiming, "My boyfriend is straight!"