Aside for the pretty standard "in the car" locations...
A little foreplay in the laundry room of one of my dorms, until a night janitor walked in...
On the balcony of a hotel room in Chicago at night...
On the side of a road in the middle of Iowa farmland, in the open passenger doorway...
On the side of a road in the middle of a different area of Iowa farmland (on year later
), fully nude, on the hood... (both times around 6pm on a summer Sunday)...
Twice on a park bench a few blocks away from my house, in the middle of the night, relatively close to the road but obscured by some trees (once in the rain)...
Once in the large field of the same park, again in the middle of the night, fully nude...
Oh, and some fingering underneath a blanket while in high school on a plane to Europe with our band director sitting right in front of us and either my dad or my best friend (I forget which) sitting next to me on the other side