Amazon Prime’s “Citadel,” which stars Meghan Markle’s pal Priyanka Chopra.Chopra, 41 — who plays the series lead, agent Nadia Sinh — has been a close friend of Markle’s since 2016, when they met at Elle’s Women in Television event.In the third episode of “Citadel,” which dropped earlier this month, Nadia sends Mason Kane, played by Richard Madden, to meet with crime honcho Balduino Basto.Balduino, played by Sen Monro, is asked to help break into the office of the armed forces chief, to which he exclaims: “The chief of armed forces? You might as well have asked me how to get between the legs of the Duchess of Cambridge!”The Post reached out to Amazon for comment.The line coincides with a clever critic noting what seemed to be a reference to the royal family in the live action remake of Disney’s “Little Mermaid,” starring Halle Bailey.In the scene, Prince Eric guesses Ariel’s name — because she traded her voice for legs — asking first if it is Diana, then Catherine. “His first guess is Diana.