Real simple dare that you can do with other things if you'd like. You need a penis for it to work though. I'm sure you can modify it to work for vaginas but I'm not gonna try and figure that out.
Real simple, get two diapers and after you've powdered your naughty bits put on one. Make sure it's tight against you. Then take some scissors or a knife or have someone else do it for you and cut a small hole in the diaper right above your little dick. Make sure you're careful and don't hurt yourself! You can try cutting it before you put it on but you need to be very precise.
Once you have a hole completely through, pull your penis out. So you'll be in a diaper but your penis will be free to be played with or teased if you like.
Unfortunately, little babies shouldn't be touching themselves. So put your second diaper on over your first. No hole cutting, no trying to keep your dick out of the diaper.
Now you go about your day, messing in one diaper and peeing in the other. Try other dares, maybe give yourself a time you have to stay in your new potty. Give it a try and let us know what your experience.
Have fun, little babies