Uchi no Otouto Maji de Dekain dakedo Mi ni Konai?

Based on the CG collection by Chinjao Girl. (チンジャオ娘。). My c*ck is now being seen by my elder sister and two of her friends. "Let's make it bigger!" It was just a joke in the first place but... it ended up with my first sex!? Since then they've been totally into my huge c*ck and come to my house regularly to have sex... (Source: DLsite English) Notes: - A demo was available to the players of RPG browser game Aku no Onna Kanbu: Perigee New Moon (悪の女幹部ペリジーニュームーン) on March 3rd, 2021. - Download version was delivered in advance on April 28th, 2021, announced on lune-soft's website, and physical version was delivered on May 28th, 2021. - A live-action AV adaptation (MIMK-066) was released on February 13th, 2019.