Joy when running on beach - due to being at beach, not wearing dress
I didn't care for the scenes of the two of them in dresses, I doubt they wanted to experience that. Also, neighbors would have seen their 'male' neighbor wearing a dress and become suspicious/uncomfortable.
When Albert starts showing joy when at the beach, I don't think at all it had to do with wearing a dress, hadn't he mentioned a few times in the movie his ultimate dream was to get enough money to live on a beach/near the ocean? To me, that was what all the joy was about - and he may well have run in childlike joy if he'd still been wearing his male clothing.