LONDON (AP) — Thousands of British students mark World Book Day by going to school in costume as their favorite fictional characters. But one 11-year-old found himself in a bind when he dressed as Christian Grey, the S&M-loving billionaire hero of erotic thriller “50 Shades of Grey.”

Teachers at Sale High School in northwestern England sent Liam Scholes home Thursday after deeming his suit, accessorized with cable ties and an eye mask, unacceptable.

The school said Friday that the decision “reflects the school’s high standards in terms of student behavior, welfare and safeguarding.” It said Liam returned once he had “modified” his costume.

Liam’s mother, Nicola Scholes, defended the costume, saying children knew who Grey was from media coverage. She said Liam “walked into school yesterday and every child knew who he was.”