My sister-in-law is a gal who loves sex and calls me a "virgin" and makes fun of me, but contrary to her appearance, she is surprisingly kind and treats me equally, even though I'm a gloomy person. One day, by chance, she gives me a handjob! From then on, I became her sex slave? In the end, she even made me have sex with her... As my sister-in-law tried to train me as a sex friend, we had sex many times, and I started to want to have sex without the condom I had been wearing...