1. This is a locker room. In a gym. It was built specifically for the purpose of changing one's clothes.
2. If you needed affirmation about #1, I was in there, and I was half-nekkid myself.
3. Don't try to pretend that you went in there to pee, by flushing the toilet when you were done. Since it was just me & you in there, I did not hear any peeing. Plus I saw you take your gym bag in there and emerge wearing different clothes and shoes.
4. If you must ignore #s 1-3 above, at least go into the big stall, you dolt!