I have a terrible relationship with my timid and serious sister-in-law. To begin with, she looks pure so everyone thinks she's reliable, even our parents think so, I hate her the most. If she tries to act like an older sister, I'll slap her! And I'll also perform lewd lesbian training on her to make her absolutely obedient and turn her into my sex slave●! That's not enough, I'll involve my boyfriend and her boyfriend in a swapping too! The timid sister-in-law couple were initially tearful and confused, but they couldn't resist the waves of pleasure, becoming more and more lewd… This is the true nature of serious sister-in-laws. Although I hate her, I've obtained the best toy, so I shouldn't get bored for a while.
