LULU-177 - Revenge on my gold-digger girlfriend: Turning her innocent sister into a 100,000 yen sex toy

My girlfriend treats me like an ATM, constantly draining my savings. When she refuses to pay me back, I decide to take matters into my own hands. Her innocent younger sister offers to make it up to me, so I start by asking her to show me her panties. Seeing how compliant she is, I can't help but take it further. I turn her into my personal sex toy, forcing her to pay off her sister's debt through non-stop sessions.