[Daidai Shikibu] My Plain, Serious Mom's Younger Sister is Actually a Total Bimbo Gal [Full Color]

Masaru's plain, serious mother and her total opposite — her voluptuous gal younger sister — are pulled into a forbidden family game where sisterly teasing turns to taboo. The busty, big-assed gyaru aunt with her heavy huge breasts and eager mouth coaxes her reluctant, glasses-wearing big sister toward her own son, leading to a blindfolded, trembling moment as the mother feels her son's big penis slip inside her while the aunt sloppily devours the same cock with drooling blowjobs and flicking tongue. What unfolds is a relentless ffm threesome of incestuous tension and creampie-soaked excess, where prim milf restraint collides with shameless gal hunger and neither woman can resist coming back for more.