His niece is undergoing secondary growth and is becoming a woman's body. The uncle's reason crumbles due to the unique sex appeal that only a girl can exude as she turns from a girl to an adult, leading to incest. Not knowing when the relatives will return, they indulge in an affair, and the niece, who has just awakened to sex, has her first orgasm on his dick. The sight of her writhing in pleasure for the first time is sure to excite you!!