My wife and I have had sex "in public" a bunch of times. Lots of time on the back deck (we're surrounded by trees and a fence so maybe that doesn't count), a few times in a public park (behind some trees) and once on a hiking trail (kinds dangerous cause anyone walking the trail would've seen us, buck naked. The experience is heightened with the risk of getting caught, but nobody has caught us yet. I was caught once with an old girlfriend on a beach outside of Halifax. Blew my load the instant this woman walked around the sand bar.