There is one word that's "not allowed" on cruise ships, according to a TikTok user who accidentally said it while staying on one. Marc Sebastian has documented his stay on Royal Caribbean’s nine-month Ultimate World Cruise. In the viral video, which has been viewed 4 million times, the creator says one phrase you are "not supposed to talk about." Sebastian said that when he uttered the frowned-upon word "utensils dropped, waiters gasped" and the room went "dead silent." He added that his friend had to whisper to him to tell him you're not supposed to say the word on board a cruise.