When I was first getting together with my friend, one afternoon when he was off work we went to a popular park along a creek just a few miles from the hospital where he works. We went upstream maybe a half mile where there weren't any people. Some college aged k i d s came along while we were 'involved' and he didn't stop or even let me know that they were coming until they were right upon our spot.
More recently we traveled together to upper Michigan and we 'got busy' on the beach pretty much every day. Sometimes no one was around, sometimes there were quite a few within sight.
It makes it incredibly thrilling.