I was busting for a poo when I got home from work yesterday and I put a towel on the drivers seat of my car and went for a drive. I pulled my skirt out from under my bum to keep it clean and while I was waiting at some traffic lights a lot of people crossed in front of me. I was desperate for a poo and feeling daring I pushed a huge load into my knickers and on the towel. I felt a rush of excitement and embarrassment as I messed myself but I don't think anyone noticed me if I'm honest. I cleaned up when I got home and I washed out the towel in the bath before putting it in the washing machine.