I'm 19 and a freshman in college. My brother is about two years younger than me. During my junior and senior years in high school, I used to listen to my brother masturbate. His bedroom and my bedroom were separated by a wall, and his bed was kind of noisy. So I would hear him through the wall, his bed creaking some when he was doing it. He would start, and the bed would creak for a long time. Then he would stop for a while. Then he would start, and, and stop, and after a while, he would do it fraster. Like the time between the starts and stops would decrease, but the time between the stops and starts would decrease, too. Until he would go for like ten seconds, stop, ten seconds, stop, then ten seconds, no stop and he would keep doing it, and I would know he was coming. And, of course, while I listened, I would touch my clit and get wet and I would make myself come just when he was coming. That was fun!! He would do it in the afternoon, after school, and in the evenings. Once I heard him do it three times in one day!
I never saw him do it. But we shared a bathroom in the morning (Mom used the one in her bedroom, and we shared the one in the hallway). Mom always told us to keep ourselves covered and decent when we were in there together. We shared, because we both went to school at the same time. There was a SMALL shower, and the door was "frosted glass." So we couldn't see through it. When one of us was through showering, we would open the door slightly and ask for a towel. Like I would be brushing my teeth or something, and he would open the door a crack and ask for a towel. But after a while, it was a real pain to dry off in the small shower, so my brother would just open the door and dry off in the shower. And I would see him!! And then he started just stepping out and drying off, because the shower walls were wet. So I got to see him, and when I was listening to him masturbate, I would think about him naked in the bathroom and think about what his cock would look like. I looked forward to the mornings!! And I started going topless inthe bathroom, because it was a pain to keep my bra on. So I teased him a little! And I would masturbate thinking about how he liked to see my breasts, which I'm sure he liked to look at! Of course, we NEVER told my mother!