I stayed at a hotel with a nearby public naturist lake, it had several big lawns. I had a evening walk and the place was empty, but in the middle of a big lawn totally open it was a woman riding a man, age 45 I guess. They were not naked and didn’t pay attention to me or another couple walking with their dog. We stopped and looked at them, but they just kept on, so I continued my walk. I have a feeling that they were a little drunk