Just for the background, I was married not long after high school. I thought she was the one, but after about a year and a half, I realized she wasn't. We split up, and I tried to live on my own but couldn't afford it, so I moved back in with my parents and younger brother. It was fine, but I was used to some of the things I did on my own, like sleeping naked and being able to masturbate freely. This dawned on me early one morning. I woke up with a hard-on like every morning, and that day I just kicked off the sheets and started stroking with my eyes closed. I wasn't at it long when I heard my brother say 'it's a good thing mom and dad are already gone, they wouldn't want to see that!' I sat up and grabbed the sheets and apologized, but he laughed and said it was no big deal and went downstairs.
I was a little embarrassed, but we were both guys and like he said, it was no big deal. After a couple minutes I put on my shorts and followed him. He was eating breakfast and said 'that was fast, did you even cum?' 'No, I kinda lost it.' 'That sucks, I hate when I have to stop.' I fixed breakfast for myself and we talked for a little while, and when he was done he said he was going upstairs to jack off since he didn't get to last night. After he walked off I thought about it for a few minutes, finished eating and went back upstairs. I walked up to his doorway and saw him, shirt off and shorts at his bare feet. I asked if he minded if I joined him, and he looked over and told me to pull up a chair. I dropped my shorts and underwear and kicked them off and sat next to him. He was watching some pretty rough porn and slowly stroking his cock. I glanced down at it and it was really close in size to mine, a little over six inches, but he had hair and I like mine shaved. We sat there for about 10 minutes in silence, eyes glued to the screen beating off until he said he was going to cum. He slid down and shot a big load all over his chest, squeezing out every drop. he said 'holy shit that felt awesome', and just sat there, breathing hard and watching both myself and the screen. When I could feel my orgasm coming, I bent down and grabbed my boxers to cum in, but he grabbed them and said 'forget that, just let it fly, it's way better.' I smiled at him and started to cum, the first couple squirts shooting about a foot in the air before slowing down and running on my hand. All I could say was 'you're right' and he just smiled.
He grabbed a box a tissues and we cleaned all the cum off, and when we stood up he said he was glad I'm back home and hugged me. It felt a little odd since we were still naked, especially with our still-hard cocks pressed together, but we're brothers and shouldn't let any weird feelings come between us. We put our shorts back on and went on with our day, and later we grabbed shirts and sandals and went out for lunch. That night we both masturbated again, but this time in our own rooms with the doors closed, and both of us acted proud about it the next morning.