"Miki and her husband have been married for two years, and she has been eagerly awaiting the chance to conceive a child. As fate would have it, Miki's older sister, Mina, is in a similar situation. Both are sexually frustrated.
The day finally arrives; Mina cannot help but notice the signs of arousal on her sister's husband, and decides to take advantage of the situation. With careful seduction, Mina manages to distract Miki long enough for her to secretly milk some of her own breast milk onto Miki's husband hand. Mina discreetly sucks on his nipple, extracting semen from it.
This act only serves to fuel Miki's husband lust even more, making his increasingly desperate for release. His need for satisfaction grows stronger with each passing moment, and his finds himself becoming more and more receptive to Miina's advances. It isn't long before his gives in to his desire and allows Mina to take what she wants from him. In doing so, they both achieve a cathartic release that leaves them both satisfied and energized."