How about going out for the day such as shopping or out for lunch; wearing a skirt (or shorts/trousers if you're really brave) and one of your thongs then going for a wee but without taking your underwear off. Afterwards, carry on for the rest of the day like nothing has happened.
Alternatively, maybe just a simple wetting in the garden, fully clothed just not being bothered to go inside.
Do you have any plans already where you could incorporate a naughty pee?