Full bore, totally naked sexual intercourse all the way to orgasm on a beach, behind a fairly tall growth of sea oats, as the sun was going down. Interestingly, or maybe not, is that it happened when I was 55 years old; never before, never since.
All the occassions I listed were as defined by the OP, penetration and orgasm. And, FTR, I’ve also done the “BJ while he drives” thing.
Lotsa times in the car when I wasn’t old enough to have any real other place to go, once on top of my former grade school and more than a few times in resturant and bar bathrooms.
I’ve attempted to talk people into more interesting places than that, but almost nobody ever seems to think it’s as a good an idea as I do.
I can’t believe I’m actually telling people this!
When I was 15 I had a threesome in the back of the park (which was next door to a church - oh the shame!:() with my ex boyfriends best friends. - I’d class this as public sex as we were all naked and came.
When I was 16/17 I had sex behind a social bar next to a skip. - Again, both naked and we both came.
A few weeks later I gave a blowjob to a guy behind the same skip, in turn he used his hand on me to make me come. - Part naked and both came.
I’m 23 this month - I’m so glad Ive grown up. Over the last four years my only ‘public’ sex was in the back of a car in a park car park. As mentioned before I’d class this as public sex as there was a chance to get caught and once we did by a woman pushing a pram and walking her dog!
sigh I really don’t sound like Ive got any better, do I? :smack:
I realize these stories make me sound like some kind of hooker but I swear I’m an innocent girl! Really! 
In that case:
The parking garage behind Pike Place Market in Seattle has been the site of many a tryst. Parked in one of the back rows, against the wall. I’ve gotten blown in the car, blown standing next to the car, had intercourse in the car, intercourse with the young lady bent over the hood of the car.
Back in my high school days, my girlfriend and I would often hop the fence around the high school pool at night, skinny dip and then screw on the deck. We also managed to screw on the 50 yard line of the football field. That’s not counting the countless times we utilized the back seat of either her or my car, parked somewhere.
As far as public sex is concerned I count everything that involves penetration and/or orgasm. I blew my boyfriend on the subway and I count that as sex because of the oral penetration. I rode him on a bus and I count that not only because of the penetration but also because I came (the bus hit a bump and caused him a bit of pain so he didn’t finish unfortuately.) If I jerk him off or he fingers me or whatever then I would count that also.
I screwed a girl up against the statue of Queen Victoria in Albert Park one summer evening.
The girl in these episodes refers to several women I dated, not always the same one:
-At night, sitting on a lifeguard stand on the beach- full vaginal, she was in a skirt and topless, I came.
-Saturday afternoon in the spring, in my car while parked on the street at the South Street Seaport, NYC, people walking by on the sidewalk- she in sundress & no panties, riding me while I was in the driver’s seat- both came.
-public park, sunny day in the summer, a little ways off the walking path, behind a tree- she wasn’t wearing underwear, hiked up her skirt and masturbated herself to orgasm, then turned around and I took her from behind- we both came.
-several times she blew me while I drove, once while going through a tollbooth- this was before EZPass and the booth had an attendant, handed her my ticket and money, waited for change, girl giving me head the whole time.
-got hummers on the roofs of several buildings in NYC, all at night, I came each time.
-a couple blowjobs in the women’s room at NYC clubs, sometimes I came, sometimes not.
-countless times I fingered her to orgasm while I drove.
-a few times she jacked me off while she drove.
-several blowjobs in the back of NYC taxis, most of the time I came.
-once she lifted her dress and masturbated for me in the back of a taxi, she came.
-many times, full vaginal and/or mutual oral, mutual orgasms, on the back deck of my house. Not sure if this counts as public since it’s on my property, but if the neighbors were looking in the right spot, we’d be easy to see.
I don’t think you necessarily have to orgasm for it to count as sex in public, although I agree unzipping, stabbing a couple of times then zipping up again wouldn’t count in my eyes.
Personally, I’ve given my boyf a blowjob on the dancefloor of a club (we had quite an audience), given/received oral in the toilet of a nightclub, had sex in a car whilst in a car park several times, had a quick mutual wank in the woods. Like Antinor1 I wouldn’t count all the stuff in sex clubs/bath houses as they’re not really public.
School football field.
Public park, numerous different locations (swings, paths, bridges, open fields, etc).
University washroom.
Suburban sidewalk.
Random farmer’s field.
Car.
Side of the road.
Tied to tree branch on the edge of university parking lot.
Most recently, completely naked on our basement entrance, girlfriend tied to the second-story porch support leg. This is probably the most scandalous as the sidewalk is mere meters away and anybody walking would have, without any problem, seen and heard us. Not scandalous in and of itself, but her wrists were tied around the porch leg so no matter what, to free her, I would have had to spend a good 30 seconds unwrapping her wrists. (For the record, two people cycled by, neither stopped but both looked. And yes, we were drunk.)
How public is public? In the woods, 'way off the path, on private property? I didn’t think that one would count.
Just after nightfall, standing in the driveway, next to my parked car? I’d say it would count as the neighbors on both sides and in front could very well have been watching through their windows. Ditto the blow job I gave him in the front yard AND his going down on me sitting on the tailgate of his truck.
His neighbors have to hate us.
Or really really like you.
On top of the new Engineering building on campus one afternoon. Only dicey part was when a helicopter went over nearby. Don’t know if they noticed, but they at least had the good grace not to stop and hover.
In the elevator of another building on campus, while taking an evening roller skating tour of campus with some friends. It was only a 3 story building and we pushed all of the buttons on elevator, so it was sort of like Russian roulette.
On the beach at night (not recommended – too much sand).
In the water off the beach on a crowded summer day.
Driving my then girlfriends car over the causeway coming home from a night out (oral – fairly dangerous, at least as much as talking on the phone while driving – again, not recommended)
Oral given on the hood of the car in front of a house a bunch of us rented. Probably around midnight- 2 am.
Multiple times in the swimming pool of an apartment where I lived for a while. It was late at night, but would be surprised if someone weren’t peaking out the curtains.
Those are the times I’m recalling right now, probably a few more, but possibly more mundane. FWIW, I don’t even consider myself an exhibitionist. Maybe more an opportunist.