Why would a guy suddenly hate his female friend?

[Deimy]

He is normal with his other female friends but with her he is different: sometimes it seems he likes her the other he just acts like he hates her. She did nothing bad to him and he said that she always was a good friend.

[Siren777]

He might have mental issues and needs help. He could be going through some stuff and projecting on the people he cares about. It is not your responsibility to put up with his behavior as it's tumultuous and exhausting and will leave you feeling sad.