My Big Sister
When i was young...like in kindergarten, my older sister (7 years older) used to babysit me even when my mom was at home just so mom could have some free time. My sister used to tickle me until I wet my pants and then she would take me to our mom and show her that I was wet and ask if she should put me in a diaper. Mom always agreed and, believing it to be a reversal of my toilet training or something, began diapering me as a preventative measure...of course with my sister in charge. She and her friends used to tickle me often and treat me as their real-life baby-doll after that.