My Sister is My Wife
My Sister is My Wife Vol 1-2 (English) [Complete]
Hentai manga by Tsuyatsuya. Story of Yuji Agatsuma, while starting college he moves in with his married older sister. However night after night he has to listen to his sister’s passionate cries of intense sex with her husband. And his sister has matured to a beautiful and sexy woman. He can’t get Aya out of his head, and no lover can completely take her place..
127MB 360pages

Spoiler Happy ending. Married sister end up pregnant. Husband has no idea that he is not a father..