Is this place on premise, is sex allowed everywhere or restricted just to hotel rooms.

This is a clothing optional resort. Just because everyone is nude doesn't mean everyone is having sex everywhere. The people here have class and being nude doesn't always involve sex. It's been known to happen and during specific lifestyle events there may be designated areas and time where that would be acceptable behavior. Consult the resort calendar for those types of events.

I may have had relations under the water fall

There is an evening mingle pool that is off to the side from the nightclub where sexual activities are generally permitted, but the main public areas generally do not.

Sexual behavior is not allowed in the common areas, but only in private rooms.

While we are lifestyle-friendly, we are not an on-premise style club. Our resort offers multiple opportunities for people to meet others in a sexy and accepting environment. But we do not have an official "play" area within the resort. Our various accommodations offer ample opportunity for members and guests to explore their relationships.