Only certain rooms can have 3 people. I think the ocean view standard rooms have 2 beds. If you are premier members the 3rd person pays $100 a night extra. Non members maybe more. Phone resort to confirm
We added one person on in December for 1 night. It was about $80. Not a big hassle, UNLESS you booked on the 3rd night free deal. Just talk to the front desk or premier desk.