@steve25805 suggested I lay my clothes in a little heap and pee all over them. This happened a couple of months ago but I've only just had chance to post it.
It was a normal day at work and I couldn't wait to get home for some excitement. I made sure to drink plenty of water and skipped my afternoon toilet visit so I would be desperate by the time I had to drive home. I was wearing my usual work clothes, a black pencil skirt and white blouse, underneath was a lingerie set from Boux Avenue (