The Enterprise Incident originally had a much sexier scene with Spock and the Romulan commander

In Vulcan lore, romantic advances have always been made with the hands, as seen in “Journey to Babel” when Sarek held Amanda's finger. Robert Justman, one of the co-producers of the third season of Star Trek: The Original Series, almost changed that when he suggested adding a more romantic scene in “The Enterprise Incident.”

Not only did Justman want there to be a brief romance between Spock and the Romulan commander, but he also wanted it to be more heated. Producer Fred Freiberger agreed, and when the script, written by DC Fontana, came back to her, that particular scene had undergone a hotter change, according to These Are The Voyages Books.

In it, Spock “rained kisses on every square inch of her [the Romulan Commander] shoulder.” While he tells her that she is beautiful, she lies down on the divan in an “inviting pose.”