Id prefer a British model for this, just for authenticity.

You are a on a live tv chat channel like Studiio66/Redlight Central/Babestation in the last five minutes of your show. It is a day time show so you have on a short dress and lingerie. You are desperate to pee but the producer won't let you leave till the show finishes. The producer tells you they might let you leave early if you tell them about being desperate and about any time you have, or seen any other girls wet their knickers before (If you haven't just make up some stories where you accidentally pee in your knickers). You tell the producer you are not sure you can hang on and are told it'll just be a few more minutes. Before the show ends though you lose control and pee in your knickers and your dress. You end with a little bit talking about how embarrassed you are wetting yourself on live tv and how naughty you feel doing