The Boy in the Dress, by David Walliams.
Dennis is a 12-year-old boy whose life has been very boring and lonely since his mother left a couple of years ago. He is bullied by his brother and his father has a “no hugging” rule in the house. The two bright spots in Dennis’ life are soccer — he’s the star player on his school team — and fashion (but don’t tell his dad). He befriends Lisa, one of the fashionable girls in school, when she finds out that he reads Vogue. Then Lisa has an idea: what if Dennis went to school dressed up as a girl? It’s a great idea… until everything goes wrong.