This story takes place when I was 16 and my younger brother, Sean, was 13. We have a laundry chute outside of our bathroom, so whenever my brother was going to get in the shower, he would take off all of his clothes and put them down the chute before entering the bathroom. So, once in a while, I would catch a glimpse of him naked. I could see his dick with a small amount of hair and many times, he had a boner for some reason. It was sticking straight out. His dick wasn't very big considering he was only 13.
I was never quite sure that my brother jerked off until one day. I always had some suspicions to why he went into his room sometimes with the door shut and came out 15 minutes later. I figured that was what he was doing, but wasn't sure.
Anyway, one day, I was laying in my bed watching TV when I heard my mom calling my brothers name from the basement. But he didn't respond. So eventually, she called my name, so I headed to the basement. My mom had a basket of clean laundry that she wanted me to take upstairs. The basket contained my clothes and my brothers. So, my mom told me to take my clothes out and then give the basket to my brother. I headed back upstairs to my room and took my clothes out of the basket. Then, I went over to my brothers room across the hallway. I opened the door not thinking about what he might be doing and got the biggest surprise of my life. Sean was laying there, stripped his clothes on the floor, boxers around his ankles, headphones on, jerking off to porn.
He had no idea that I even opened his door because his eyes were shut and the headphones drowned out any outside noise. I was still in shock. I realized that I had walked in at the moment that he was cumming! Two seconds after I walked in, he sprayed cum all over his chest. Then, I called his name, and he opened his eyes, took off the headphones, and looked at me with cum still dribbling out of his dick, and said,'Sorry, I didn't know...' This was one of the biggest cumshots I have ever seen.
All I could say was 'Lock your door next time.'