PHOTO: Kensington Palace

Kate Middleton is no stranger to fashion controversy. In over a decade as a member of the royal family, the Duchess of Cambridge has had many fashion uh-ohs, including wearing dresses that went above the knee, holding large bags instead of small clutches, and wearing black. But this might be her most daring look yet! Just yesterday, Kate was spotted at a children’s charity function wearing nothing but a BDSM outfit.

A source close to the Duchess told Speople: “I don’t see the issue. The palace forbids women from wearing pants, and Kate was not specifically wearing any pants. The palace said to cover your head and she did.”

In fact, Kate wore a devil horn headband. “Okay so wasn’t a hat in the traditional sense,” said the source. “But our Kate is anything but traditional!”

However, official royal protocol explicitly forbids any member of the royal family from wearing a leather thong, unitard, or studded choker. Looks like Kate needs to double-check the rules next time!

According to attendees at the event, which took place at a children’s hospital in London, Kate was the picture of politeness and grace. “She’s so relatable!” one nurse said.

Prince William did not appear to be a fan of his wife’s outfit choice, however. He admitted that the strappy outfit was “much too conservative” for him. “I was really disappointed in her,” the Prince was heard saying to friends later in the evening. “Turns out she’s a prude, just like the rest of them.” Prince William is reportedly frustrated with Kate, whom he called “redonkulous.”

Earlier today, Buckingham Palace released a disapproving statement about the whole affair, saying: “The Queen hates any form of submission.”