>>8713968
>sister NTR
only one comes to mind, Touchuukasou by fuetakishi
>https://hitomi.la/doujinshi/touchuukasou-english-225468-1189711.html#1
terasu mc and ntrman made similar things
>https://hitomi.la/cg/short-comic--21-english-3156890.html#1
>https://hitomi.la/doujinshi/cock-that-makes-tomboy-sisters-tap-out-english-3447810.html#1
terasu's Kokujin no Tenkousei NTR ru series should count too
the artist 'Rannero' seems to focus on it
>https://hitomi.la/artist/rannero-all.html
few works touched on the subject
>https://hitomi.la/cg/terasu-mc-fanart-to-be-useful-%E0%B9%84%E0%B8%97%E0%B8%A2-3111575.html#1
>https://hitomi.la/doujinshi/15-sister-gets-ntr-d-by-her-stepbrother-%E4%B8%AD%E6%96%87-2988576.html#1
>https://hitomi.la/cg/%E5%A4%8F%E4%BC%91%E3%81%BF%E3%81%AB%E7%94%B0%E8%88%8E%E3%81%AB%E8%A1%8C%E3%81%8B%E3%81%AA%E3%81%8B%E3%81%A3%E3%81%9F%E3%81%B0%E3%81%8B%E3%82%8A%E3%81%AB%E3%80%81%E3%82%A4%E3%83%88%E3%82%B3%E3%81%AE%E3%82%A8%E3%83%AD%E3%82%AC%E3%82%AD%E3%81%AB%E5%A7%89%E3%81%A8%E6%AF%8D%E3%82%92%E5%AF%9D%E5%8F%96%E3%82%89%E3%82%8C%E3%81%9F%E3%83%93%E3%83%87%E3%82%AA%E3%83%AC%E3%82%BF%E3%83%BC-%E6%97%A5%E6%9C%AC%E8%AA%9E-2766560.html#1
>https://hitomi.la/manga/nettori-netorare-bijin-tsuma-inniku-choukyou-genteiban-%E4%B8%AD%E6%96%87-2574578.html#1
not sure how 'sister NTR' even works though