Kinda late to the party, but whatever.
Not even going to bother making a throwaway.
So, I must have been about 8 or no older than 9 at the time..
I had one friend on my youth soccer team who I would stay over his house on the weekends when we had a tournament or multiple league games.. Let's call him Mark.
I loved going to Mark's house. He was super rich, had a huge house, a bunch of really big dogs, all the coolest stuff to play with, a nice pool, you get the point- everything I didn't have.
Probably on the third or fourth time staying there, it all started with Mark in his bedroom before breakfast. His older brother comes storming in the room and, while laughing, asks- "Hey Mark, wanna have a nice glass of J-O after breakfast?"
I was confused and it was obviously some sort of inside joke that I just wasn't a part of. Mark tells his brother that we'll all drink some J-O.
We go downstairs to eat, shit pretty much is all normal. I do notice, however, that there was orange juice on the table (we call it O-J in America, dunno if that's normal but is pretty important for clarification).
I reach and grab the bottle, pour myself a glass. Mark asks me for the O-J. I'm now super confused because whatever the hell they were talking about upstairs definitely wasn't orange juice.
We all finish eating, Mark looks at his brother and says, word for word, "less O-J, more J-O."
We clean our plates and head upstairs.
Mark leads me to his room where he makes me swear to not tell anyone about this before he shows me. (Hi guys!)
He leads me to his brothers room, where his brother (maybe about 12) appears to be naked under his covers, and.. to be blunt, furiously jerking off.
I get ridiculously uncomfortable and want to leave, I look at Mark, who is smiling from ear to ear. I kinda just sat there, I was basically in shock. Mark, without being asked, got on his brothers bed. His brother is still just going at it, bottle of lotion right next to him.
Still kinda unsure as to what's going on, I look up to see why Mark got on the bed with him while he's pulling on his dick like that. That's something I've just never seen before.
His brother looked at me while I poked my head up. He put both of his hands in the air and goes, "look, no hands!"
Mark was jerking him off. Yes, that's his full brother.
Mark looked at me and said, "you can do it to yourself, too!"
I literally just left the room. I pretended like it didn't happen. I just went to the other bedroom and noped the hell out of there.
Luckily, that was my last day at Mark's house of the weekend and my mom had picked me up just hours later.
I also want to note that I got the best deal out of this experience. I got to discover masturbating, definitely realized my teammate was one of those gay people I hear about, and even though that's how I discovered it, I still immediately knew some shit was wrong about the way they were doing it. I, to this day, prefer jerking off WITHOUT my brother.