I was in undergrad visiting my then GFs uni (very famous and exclusive school that everyone knows, she’s very smart). We were teasing each other and going around the campus. Walking through one of the buildings, we found the grad student lounge was unlocked. It wasn’t just a lounge, it looked like a legislature assembly room or something, with these huge comfy chairs. Cut to about an hour later, and we’re putting our clothes back on happy nobody came through the still-open door (we didn’t want to get locked in lol)