I was allowed to stay at my aunt's place in Tokyo to attend a university open campus. Her husband was away on a business trip, leaving just the two of us. Furthermore, seeing my scrawny body, my aunt forced me to join her daily workout. Since I hadn't seen her since childhood, I found that she had been training on her own, staying beautiful despite her age, and above all, exuding an intense adult sexiness. Tempted by her exposed breasts and the jiggling of her huge ass, I got a full erection. Then, whispering dirty talk and rubbing my dick, she shook her firm ass wildly and cheerfully began a vacuum-sucking, pounding cowgirl piston ride. With her relentless hip movements, I came again and again. Thus began the intense days between a carnivorous instructor, a stunningly insatiable beauty, and me, a scrawny, introverted guy.