Is this to sterotypical to put in my book?

You imply that if a guy isn't stereotypically gay he's in the closet. That's not true. Not all gay guys have a secret inner Queer Eye for the Straight Guy inside themselves- so yes, I think it would be stereotypical to make him a fashionista, especially if that's his "gay" side and his "beer and sports" side is his "normal guy" side.