Outdoor hotel swimming pool, with another couple (our friends who we were on vacation with) going at it on the other side of the (small) pool.
Ala Moana Beach on the island of Oahu, Hawaii on a Saturday at about 2pm. We swam out to the reef, and my girlfriend of the time was wearing this skimpy little bikini, the water made her all shimmery and, well, sexy. We did it right there on the reef, watching all the people on the beach who we guessed were watching us. So hot and dirty.
Not my story, it was told to me by someone on the interwebs (take for what it might be worth):
The front lawn of Ho Chi Minh’s tomb in Hanoi.
The Embassy of the Czech Republic in Ankara, Turkey. Twice. At least.
Where does one get pins??? 
Bah, show me something. Give me on the tomb!
(Fuck you, Ho Chi Minh!)
A good friend of mine is from Moosomin 
I have two memorable ones.
One was on my honeymoon. We were at the ocean shore (I wont call it a beach since there was no sand) and we were in a nook made by the rocks, and about 2 minutes after we finished 3 young boys and their Dad walked by.
My husband and I have driven across Canada a few times and are only one province short of a full set. We haven’t been to Newfoundland so that is the only outstanding one. There was this problem with Manitoba though. We never actually stayed overnight in Manitoba. So on our last trip we kept talking about pulling over, but never did. When we reached the Manitoba Saskatchewan boarder we pulled over behind the Welcome to Manitoba sign and crossed it off the list.
Hmmm. I was just there last month. It’s heavily guarded, to say the least. I’d have to know the logistics of that.
Most recently, five stories up, on the roof of my apartment complex overlooking the courtyard, shopping center, and busiest highway in town.
Then there was that school bus someone apparently forgot to lock. Before that, a girlfriend and I climbed to the top of the traffic signal thing trains use, and I timed my orgasm to the second the train passed. It wasn’t until then that I realized it was a passenger train.
In a castle ruin on the Isle of Skye. Fun that.
I got a blowjob while driving at 90 mph in the fast lane of the M1 on the way to Scotland.
For sex, it’d be by moonlight in a lagoon in the South China Sea - with someone else’s girlfriend. :eek:
A loonngg time ago, I used to work private security. I was assigned to patrol a new subdivision that was under construction. The guard in the next subdivision was female and hot. One night we decided to go up on the second floor of a house under construction. It was almost completely finished and had carpet on the floor and big mirrors on the closet doors.
Oh, yeah, baby…
Probably in a horse barn in Germany. For country boys a barn doesn’t sound too exotic but I did not spend too much time around barns or farms.
2 come to mind and they happened only a few months apart. The first was on an old log next to a maintainence shed at Yellowstone National Park about 40 feet from a community campground firepit full of folks. She was a part time ranger from Missouri.
I wouldn’t call the next place exotic but it was the women’s restroom at the downtown Seattle Nordstrom store. If this gal had her way it would have been on the Space Needle elevator or on the monorail.
Mile High pins used to be available at most small airports; don’t know if they still are. I guess I could replace mine; I don’t think you have to have witnesses or anything.
ETA don’t know why this quote looks so odd; nor how to fix.
West Virginia.
That brought back memories. My sex at Antioch was confined to the dorms, and once in my car behind Mills Hall.
Library of Congress.
What section?
Was a longtime ago, but IIRC it was in some sort of fancy conference room off the exhibit hall (and really, who doesn’t get hot and bothered when seeing a Gutenburg bible).
(also one of the neater places in DC to visit, even aside from the nookie).