Mayu: "Uh- ummm..."

Yes, Mayu-chan, go ahead.

Mayu: "Why is kei-kun here?"

Mayu: "That's why I told kei-kun, It's completely impossible! We're siblings!"

Mayu: "...!"

okay, this is a good chance for you, so today we will start having brother-sister sex, kay?

Kei: "Sis, Sister..."

but, I've used little brothers briefs to masterbate, that's what you want to tell me, isn't it?