Meghan Markle may have committed a royal faux pas Tuesday as she celebrated the 100th anniversary of the Royal Air Force. Duchess Meghan crossed her legs. Strict protocol calls for her to slant her legs, like sister-in-law Duchess Catherine. “Most royal ladies choose to sit with what they have nicknamed ‘the Duchess Slant,’” royal expert Victoria Arbiter told Inside Edition. Markle wore a black Dior dress with a boat neck, channeling the legendary Audrey Hepburn.