HUNTC-069 "Big brother, there's a hidden option... what should we do?" My sister is my brother and I have a high-paying hidden option part-time job! I have a super naughty sister! When my sister doesn't have enough pocket money...

I have a super naughty little sister! When she doesn't have enough pocket money... she massages me and begs me for money in a sweet voice! I have no choice but to give her a light massage and 1000 yen pocket money, and she gently approaches me and whispers, "There's also a hidden option?" I'm skeptical, but I order the hidden option! Then my sister does something naughty... Before I knew it, she'd inserted it with all the hidden options! I was completely sucked up by my sister!