At the request of her sister and husband who have a sexless marriage, she somehow ends up taking her sister's place for her brother-in-law... "How did it come to this?" the older sister wondered, feeling conflicted. Yet, there was a reason she had to accept her sister's plea. Though bewildered by the impossible request, she gradually opens her heart and body to her brother-in-law, who shows how much he needs her. Despite knowing it's wrong, the pleasure becomes irresistible. Before she knows it, the sister is completely lost in the moment...