I don't think Bananaman has done anything wrong, he was curious about this new member, and wanted to understand how she had gotten into AngryAnimals so quickly. At the time he was not aware that many of the AngryAnimals members already knew her quite well, and was unsure as to whether it was because she was female. While some people might view this as sexist, I think that it is quite often reality. While the AngryAnimals players may very well be an exception, male gamers are often much nicer to female gamers than to other guys (It's just part of human nature). He was not outright rude to her, and actually asked her a few genuine questions. Guys (and Girls), if you think about this reasonably, it would be fair to give him a chance.

Of course, Candy is probably used to getting abuse about being a girl, and jumped to the conclusion that Banana was being sexist. Her reaction was understandable, but seemingly mistaken.