A boy prone to premature ejaculation wants to be gently teased, and a big sister wants to feel it. The big sister not only uses her licking technique, but also presses her bare skin against his to gently escort his sensitive cock. However... the moment the boy requests a "nipple job", the big sister's expression stiffens! That's right, the big sister has such sensitive nipples that she can cum just from her nipples! When the big sister starts to give him a nipple job, it seems she feels too much and the nipple job goes full throttle...