I usually fall for women because of their personalities, but my girlfriend's adult sister Rikka is the cutest woman I have ever met—and she keeps secretly tempting me. I know I should avoid her, yet she is impossible to resist. During our three-night stay, Rikka insists that a handjob is not cheating and closes in on me. Guilty about betraying my girlfriend, I still surrender to her devilish hands and end up ejaculating 19 times.