Right when I saw it I would probably be like "Oh shit, sorry!" and turn away. Granted it could be intriguing to see them like that, I feel just staring or hiding it would be a little weird.
*shrug* Nothing, probably. Maybe apologize if they are embarrassed? Perhaps I'd get out the tea set and have little tea party with them. Or maybe get those awesome bubbles for baths and have a lame bubble party. Mayhaps even get out the rubber ducks and have a duck party. Or just have a party. Ain't no party like a bathing party.