[Sawaraya Shoten (Sahara Gensei)] Nitoubun de Ii yo ne (Gotoubun no Hanayome) [Revelations72]

Nino and Miku Nakano turn their study sessions with Fuutarou Uesugi into a heated sibling rivalry where 'it's my turn now' is a claim neither big-breasted sister intends to honor. When Miku catches Nino breaking the rules by moving in on him first, their tug-of-war over their tutor erupts into a ffm threesome—one girl riding his big penis while the other rims him from behind, sweat-slicked and giggling over who he'll choose. By the time both sisters have had their fill, the question of sharing him in equal halves gets answered the only way they know how: together.