There are a few college guys at my gym who will shave naked in the bathroom mirror between the time they leave the sauna and take a shower. It's quite hot, as they all break the stereotype about young guys being more prudish than generations before (although in general, this is still the case).
They are generally there during non-peak times, so at most, there will be like 3-4 guys who will see them. I don't stare because I see them naked in the sauna/shower literally almost every day since we're all gym regulars. If it was a one off occasion where I wasn't a member of the gym, or some new guy came and did it, I would definitely take a few peaks.