Since I hadn't exercised lately and my body had become flabby, my wife suggested I get some training from her friend Yui, who used to work at a gym. Yui, who continues to train on her own even after marriage, has a stunningly beautiful body, and I was inwardly nervous just at the thought of training alone with her. Then, on the day of our session, as Yui, dressed in tight-fitting sportswear, gave me hands-on guidance with my workout, I unconsciously got an erection...
