I'm 19 right now. I live at home because my family refused to pay for housing at the college I go to nearby. I live with my parents and my little brother Mike. He's 16 now and a cute kid. He's about 6' and a solid build.
A couple of years ago (I was 17 he was 14), I accidently saw him playing with himself when I was trying to find something for a school project in the attic and I saw down into his room (there was a vent there that I had thought was for heat but was obviously not used for anything). He had just taken a shower so he was completely naked and still a little wet as he sat on his bed looking at what I think was the Sports Illustrated Swim Suit edition that my parents jokingly bought for him. He spat in his hand for lube as he used it to stroke his circumcised reddish dick that was probably around five inches long. I just watched as he enjoyed himself and came into his towel completely silently. He didn't grunt or anything or even breathe loud. The only sound I heard the entire time was his balls slap his body when he sped up once. The entire thing took like five minutes and made me so wet. I was about to jill myself off when my mom called up to ask if I was doing ok. So I quickly grabbed what I needed and descended.
The next day my parents were out at night when my brother showered so while he was in the shower I crept upstairs into the attic to see if I could catch another glimpse. I did. I saw him cum again.
I didn't do it the next day because my parents were home and would be suspicious that I was in the attic. But that weekend they were out again so I went up, this time with the camera I got for Christmas. I decided that I should tape his shows instead of watching them live. So ever since then I have recorded them and watched them every sunday night and jilled to them and it has been so hot.
Mike has no clue that I do this.