Does the adult hate himself? Feel guilty over past indiscretions? Cartoonist lyrics underweight and diminutive of stature?
Absent at least one of these traits I would recommend different accommodations. Though as I've mentioned in another thread, 3 people fit on a king bed jest fine.
To be fair I would rotate who sleeps on it. I have not slept on OKW but the 2 other times at different resorts, my back could only take for a couple of nights in a row. Egg foam will definitely help.