SNTJ-013 Having an affair with a married neighbor

She wasn't angry at all but wanted me... to practice horse riding with her! The story is that Shiina Sayuri is the lover of that man, he always criticizes her poor sexual skills, especially when it comes to horseback riding. Shiina Sayuri thought that for that reason, he gradually got bored of her and came here less often. She wants to improve sexual performance and help men feel even more pleasure. And from then on I became a tool for her to practice. I was only allowed to lie still while she straddled me. But over time, she seemed to be accepting me more, no longer doing everything herself but letting me take the initiative, enjoying sexual pleasure together...