Suspecting infidelity, I've been made to wear a chastity belt by my live-in girlfriend. One day, her sister Rin comes to stay with us for a week because the construction noise is keeping her up. I catch Rin fresh out of the shower and can't help but get an erection! My chastity belt is discovered by Rin, and she starts teasing me with it... and so begins Rin's week-long mission of controlling my ejaculations with pussy licking! "Can I borrow your breasts, big sister? I can't take it anymore!"