[Zetsubou Shiromuji (Shousan Bouzu)] A Day At The Mansion 3

Two bunny girl sisters wager their bodies in a mansion full of thick, older men where every lost round ends with a cock buried to the hilt. When the blindfolded younger sister's timer hits zero, her defloration becomes spectator sport, her gagged cries and jiggling breasts on full display as her sibling screams for someone to save her. By the final round both girls are stuffed airtight, the self-proclaimed sprinter pleading through her ball gag against any more nakadashi even as her body begs for the next load.