In The Wednesday Wars by Gary D. Schmidt, why does Holling tell Mr.Goldman that he no longer wishes to play the part of Ariel?

Holling does not want to play the part of Ariel, because Holling is a seventh grade boy.  Ariel is an unbecoming character to a young adolescent male, because Ariel is a fairy, and Holling thinks that being a fairy is a part for a girl.  In fact, even Meryl Lee thought it was a part for a girl.  That is why Holling tells Mr. Goldman that he can't play Ariel.    

Let me tell you, it is not a good thing for a boy from Camillo Junior High to play a fairy.

Mr. Goldman will not hear any of Holling's arguments though.  Then Holling is given his costume, and that is when Holling really does not want to play Ariel.  Not only is Holling going to play the part of a fairy, but he has to do so while wearing a costume comprised of yellow tights with white feathers on the butt.