Not directly in the open, but sex with the danger of being discovered is fun.
It started in the lecture hall after the lectures. (we had planned to just use the grand piano there to practice music. Her playing the piano, me singing. But things somehow escalated)
Then in the park hidden behind bushes because the first time was so exciting.
Then in a janitor's room in a disco. Then on a closed gallery in a theater while in the foyer a ball was going on.