Check out Vahine Island. For Tahiti it is actually reasonable to stay in an over water bungalow. It's on a 15 acre atoll so it is much more private. Only 3 over water bungalows and if you request the one on the end you'll have complete privacy. We stayed there a few years back and we're never concerned about a lack of clothing. The food is incredible, the view is incredible, they have a glass coffee table in the water bungalows that you can open at night and feed the fish ( and the sharks!)
By the way you can take a day tour where you have an opportunity to get in the water while they feed the sharks. A once in a lifetime experience!