Back in college I had a job at a restaurant which was located in the MPLS Skyway system. One of the perks for the Skyway tenants was that the employees had exclusive access to GYMs built specifically for tenants at the Skyway level, these spaces had solid walls. And one of the perks of working at a restaurant is that you get laid a lot, if you play it right.
Long story short, a professor who used to lecture at a specific university in downtown MPLS used to frequent the restaurant a lot, and we had the hots for each other. Problem was that she was married and couldnt bring me to her place, and I was broke as F*** to afford my own place. So when I did make my move, I floated the idea that we could use the gym, since it was mostly unoccupied during the 9-5 hours and she agreed.
Oh the the thrill of having sex in a public place, where every wall has mirrors with the threat of getting caught, especially when you can hear the general public walking just a few feet outside those walls
I was 22 at that time and she was 37. I want to add that she was a marathon runner as well.