In a tanning booth, on the tanning bed while the clerk was at the front desk...

Very interesting

That spings to mind... a roof top terrace overlooking a street full of lades of negotiable affection to the right and a local football (soccer) stadium in front where a match was playing. The lady was my GF at the time and not one of the women downstairs. Just happened hotel rooms were all booked up and this was all that was left, in the red light district. The warm night air was wonderful.

In a hotel public hot tub. Closest above would seem to be semi public, so that's how I voted.

In a park and on a remote place on a beach.

I love outdoor sex and having people watch me get used by groups of black men

dfw airport family bathroom

Back seat of a car as a friend drove it around town. On the hood of a car on a dirt road as a few people drove by.

graveyard across tombstone

Me cemetery, bar, pick up trucks in the bed with blankets and such, park, hiking trails. Adult store

Can add a few more. In a multiplex tgeater, fir sale open house.