A Wedgie Slave
Eric, a 15 year-old boy, stumbles upon his best friends 17 year-old sister hanging in a closet with nothing on except her wedgied panties.
To prevent Eric from telling, Samantha offers the deal "If you don't tell anybody, when you come over I will be your slave. Meeting any and every demand you seem fit."
Thus a new relationship is formed, read about some of the adventures.