https://www.dlsite.com/ecchi-eng/work/=/product_id/RE272578.html

A futanari girl gets caught masturbating by her older sister,
and in her shame and confusion, ends up sexually assaulting her.
From that day on, the two of them enjoy an intense sex life.

I want a futanari sister this lewd...
Alas, I doubt they would find me attractive.
Definitely a lovely set I was enjoying looking through!
I would love to see this translated at a later point!
Thanks for this as well, LvdvE!

Base +13, Yuri Rinoa -7

Very difficult to translate this, because you have to redraw some parts, the kanji are directly on the art and there are not bubbles... all you have to do is hope for someone brave to do it.
I asked for the raw version on DLsite, but I don't have too much hope, and then I don't know of a way to contact the artist.

Base +4, orvu +6, Seelenmord +11, proxy +6, Sexyshinx2 +2