https://www.dlsite.com/maniax/work/=/product_id/RJ01124124.html
https://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_315913/

>This is a story about a family that had been married for more than a decade.
>A happy family with a good reputation among the people around them.
>Except for the fact that she and her husband are sexless.
>One day, her husband's sister, who lives abroad, asks her to take care of her son Paul.
>She likes Japanese culture and wants to do a homestay.
>Being half-Japanese with a foreign husband, Paul is large and she was reluctant to let him live with her daughter, who is still a student but not yet old enough to be a child.

Base +13