Me and my sister-in-law share a room. Naturally, there was only a simple partition, so I could see my sister-in-law changing clothes and sleeping! One day. I was horny and slowly inserted my sister-in-law while she was sleeping so that she wouldn't find out. I can't help but cum inside my sister-in-law's pussy, which feels so good even without moving! Then, my sister-in-law...actually seemed to be awake, and asked me, "Brother, why won't you move me?" She moved her hips herself and asked for sex! If this was the case, I should have done it openly. How excited I was...