BUT be mindful that if you were to book a room for "them" using your MTO, technically you would be assigned to that stateroom and your spouse to the other, therefore your room charges (photo on KTTW card, so you could not swap), your lifeboat assignment, your photo package will all be tied to your friend's spouse and not your own. We sailed MTO and it really would not be worth it to me to try and save the money to be in separate life boats, share on board accounts, photo packages, etc. Yes, technically, you could swap rooms and sleep with your spouse, but your room keys will not work for your spouses room, so you will not be able to get in to your own room...