Transgenders and My dog locked me out of my house

It has been an interesting couple of days. First off, my dog locked me out of my house. I went out to my car to get something and my dog didn't like that. She jumped on the door and somehow, her paw hit the latch on the door and pushed it down. Good news, 3 neighbor guys came over to help get me back in the house but it took an hour. Another thing that happened was that I almost offended someone. At work, I had to watch the fitting rooms for a while. A guy came up to me to try some dresses on and he was wearing a dress and make-up on. Hey, if it makes him happy, I am all for it but I didn't know if I should let him in the men's changing room or the women's. I wasn't sure if he identified himself as a man or woman and I didn't want to choose wrong and offend him. Finally I decided just to pretend I was busy and I told him to just walk in and I would be right with him to unlock the door. He chose the female side. What are you supposed to do in a situation like that? Update on the happiness challenge, I am loving being able to make someone feel good everyday.