Oneechan’s Daily Routine [English], by Usagi No Tamago

A sister has taken the habit of tending to the sexual needs of her younger brother, she trained him since the beginning.
At this point, I must confess something I can’t explain : I simply hated that girl. I should have liked her, she’s good looking (not on the slimmest side of life, nice eyes), appreciated her sexual openness, but, on the contrary, I found myself damn annoyed with the “empty shell” feeling she gave me, and her blank vaguely smiling expression… grrr ! >_<

It’s a purely personal opinion, I can’t even comprehend why I feel it, so, well, see for yourselves ?
Credits are for Desu and Anon