I have 3 ocasions to share with you all.
1) When i was 19 myself and the current boyfriend worked together in a cafe, When we had closed for the day we would often have sex in the kitchen (i know a little unhygenic lol) even done it on the griddle once, after it had cooled down. One day a guy from the office next door came in and mentioned that they could see straight into the kitchen, he never mentioned what people saw, but we knew what! Did it stop us? Hell no!! Just made us more turned on at the fact of being watched.
2) With the same partner, pulled over one day to give him a BJ at about 3 in the afternoon was getting into it when an angry man banged on the window saying that it was disgusting and we should do it at home.
3) In the woods of our local park, was totally naked shagging away when a bloke walking his dog wandered by, we didn't stop and he kept on stopping and looking back, that was his cheap thrill for the day ;-)
...And that was my first proper post, phew!!! Done it