For our most recent anniversary, Allison and I gave one another some sessions with a trainer. Our trainer moved gyms, so we moved with him to a gym slightly farther from us (20 minutes away).
It happened that today Allison and I had a business meeting (with the same person) in the same town as the gym, Millbrae, so we shifted our schedules so we could go to a trainer session before lunch and then shower and go to lunch, for travel efficiency.
It wasn't until I got to the gym that I realized that I had my work bag but I had left home my gym bag, which had my change of clothes for lunch. Since I somewhat knew the person we were meeting (an education consultant in his 60s), I decided to attend the trainer session and not make the round-trip back home, so I ended up attending the business meeting in shorts and sneakers, post-workout... (luckily he didn't mind, though he showed up well dressed in a sports jacket so we were a bit out of synch).
(I did shower, and then put on Allison's workout t-shirt since it was large for her and kind of fit me and she doesn't sweat as much as I do since she's not as intense a Tough Mudder as me). :)