On the side of a busy interstate.
So one time me and the babe I was going out with at the time got horny. And we kinda liked a little "danger sex" or semi-exhibition sex, whatever. Pulled over onto the shoulder, got out, went to the other side of the car, started doing it standing up.
It's when the 18 wheelers whizz by and the car (a heavy one, not a compact) that you're leaning against shakes like an earthquake, and the wind nearly blows you away ... well, it just wasn't very "conducive" ...
Anyway not totally sure if that was dumb, as much as it didn't work as well as we'd thought.