I've had my breasts fondled by someone (that I know!! and allowed) in a public space before...but we stopped whenever people approached.

ooo...another..inside a covered bridge!That was cool until a car came through,saw us and i fell down and cut my ass on a sharp piece of wood!-how could i have forgotten that experience!

I guess that wasn't the piece of wood you wanted.

Yes, a few times at a nude swimming hole. On a boulder in a stream at the top of a series of waterfalls.

Also, once at at an x-rated drive-in that used to be open in Vermont. We had sex in the back of a pickup.

Great fun!

My ex-girlfriend and I had sex in the median of I-75 south of Gaylord Michigan on the way home from a long week in Detroit visiting her folks. It was quick, but really hot, not literally, I think it was December, and we were standing in ankle deep snow during the event.
My wife once fellated me in an antique store on one of our many road trips. It didn't go all the way, more just foreplay. Another time, I fingered her to a climax in a movie theater, not even an X rated one, just your normal everyday cinema.
And , lemme see, there were several times we took advantage of 2-rut roads on the way to or from somewhere, not really public, per se, but we did get almost caught by some berry pickers on one of the episodes. And I recall a blowjob on our deck behind the house, which would have put us in direct view of at least one neighbor, if they had been looking our way.
Does having sex in front of an open window count?

These were in the " early years " of our marriage, so things have simmered down lately.

Yes! over a hotel balcony above the highway. Amazing!