``It'' started with my mom's sudden death. For the next 10 years, the younger brother, who could not wean, grew up using his girlfriend's older sister's breasts as a pacifier. His younger brother's tongue movement when sucking has improved year by year. Her older sister has become more sensitive over the years, and her nipples, mammary glands, and milk line are aroused as erogenous zones. Although they recognize that their daily lives are abnormal, the older sister with her ``bug motherhood'' and the younger brother with ``crazy growth'' try to break up their distorted relationship.