And, you might now be on the internet.

I hate to be Capt. Bringdown, but everyone should realize, that the moment you step outside your home or hotel room (and I'm not 100% sure of the latter.), you're on CCTV.

So, keep that in mind when you're in a public place.

so this was before I was a provider. I was dating a married man. and he pick me up from work one day my lunch break and I knew that we were going to fool Around.
so I wore a dress with no panties
We went to a park and behind a tree. But very close to where people were walking by.

And he bent me over standing, and had sex right ther

Parking lots in Manhattan with SWs - lots of times

Years ago, once got caught be LE squad car - they gave me a "parking ticket" after I shit my pants

I got as far out of thew channel as was safe...  didn't want to get close to the houses either...   as we dared & laid down in the bottom of the boat for some action.  

A far as the OP, I doubt that the stairwell has cameras but expect the doors to the floors & outside would be covered.

In Hawaii, started on his hotel balcony, then saw people watching, so moved inside but left doors open. I was so loud that the Security came up and asked us to keep it down!  

At a bar once with friends, I saw this hottie, so we went to the gravel like area where people parked, started making out, then right in between the cars we had sex in the gravel tho  

But people were walking by.  

 
At the Power Exchange and a few swingers parties..

 
In the courtyard of my old apts

Thats all I can remember so far

I'll admit it was a red eye. My GF noticed the guy sitting next to me (window seat) was sleeping, so she took the little blanket pulled it over her head while her head was in my lap and sucked me off. About mid way through, the flight attendant was walking from the front of the plane to the back and a passenger was walking from the back to the front, she turned sideways to let him pass just one row in front of us. There was no doubt (from her wry smile) that she knew why the blanket was going up and down in my lap. My GF said later that she was surprised it took me so long, she was an exceptional cock sucker and when she would normally give me a blow job it didn't take very long. But I explained to her that I had to be composed, not like normally when I can just relax and let go. I will say it was a great orgasm

Also in a car in a parking lot, and just off a public sidewalk, in some bushes.

A provider I have seen a few times is suggesting our next encounter be on a "secluded beach," or "grassy forest bed."

Bonaventure Hotel - Glass Elevator - 26 floors worth of nonstop BBBJ ...

... then a few months later, it was my turn,DATY in the Luxor hotel elevator... same provider. (If they were watching, they weren't talkin') Ahhh those were the days!