Is this considered SA?

When I was 12, we went on a small family vacation. At the time I was 12 and he 15. We had recently started hanging out again after getting over his drug use. He was starting to hang out with me again instead of shutting himself out, so at the time, I was happy. Unfortunately, my mom had torn a ligament only a few minutes after arriving, so we couldn’t go out as we planned. Where we stayed was a nice cabin, pretty spacious. We had rented 3 different cabins. One where my mom and dad stayed, one where my great grandparents stayed and one where me, my siblings and my grandparents stayed. The room I was staying in was nice. It had a bunk like bed, their was no bed underneath but their was a ladder leading up to one. The bunk bed had wood going around the bed, so it felt like I separate room. Above that was a small square hole up top that led to a small crammed room obviously for toddlers, as it had a fake plastic window in the middle with a clear view of the top of the room. Next to the bunk bed was also a small simple single bed. I find it crazy how I even remember all of this haha. Anyway, me, my older brother and younger brother thought it would be fun if we all slept in the same bed together. My older brother recommended it, saying he wanted to do it as an apology and a way to strengthen the bond. We both agreed. Night rolls around and my younger brother decides to instead sleep on the single bed, which left me sleeping next to my older brother. We both decided to sleep up in the little toddlers hangout room for fun, moving the single blanket up there and a pillow. The bunk bed was only designed to fit one person, but was even more cramped as it was designed for toddlers, not teens. The play space up the top was pretty warm from what I recall. I only remember because my brother ended up taking off his shirt. After a while of me watching my show and my brother watching TikTok, we both put our devices down. I remember him constantly telling me to “budge closer” to him. Though, I took it as a playful gesture. He would tell me to get closer and closer whilst he got closer himself, inevitably pinning me to the wall. Which, didn’t really help with the heat having his body pressed up against mine. Once he was done playing around, we both settled, and I closed my eyes to rest. Usually I do this thing where I’ll just lay there, pretending to be asleep until I do fall asleep if that makes sense? Let’s just pretend it does. After a few minutes of this, I soon felt him drape his arm over my waist. At first, I tried not to think anything of it, but then he took it further. He rested his hand on my ass (I’m sorry I couldn’t think of any other words for that ) and slightly groped it for a while. At first I was convinced it was an accident. Well, that was until he pulled up my pj shorts to resemble a thong almost? (I don’t know how to describe it) then proceeded to just lightly slap and grope me. He would move his hand to the front every now and again, never actually touching my (area) but brushing over it. This continues on for the whole night he even takes his (thing) out and rubs it against me before pleasuring himself next to me. After the incident, I spent almost an hour in the bathroom processing what just happened. And in the hot tub there was, he was persistent on me sitting in his lap. This continued on for the other night we were at the cabin (we only stayed 2 nights. I wish I told everyone straight away to stop it from escalating, but on that first day my mom was too busy with her foot and unpacking and the next day my grandpa catching a cold and packing up.) after leaving the cabin, we stay at my grandpas trailer. In the bedroom theirs a big king sized (I think) bed. The night we were in the bed, he did it again. Then at a sleepover at my grandparents, it isn’t as bad, but he continued to tell me to move impossibly close to him and urged me to take off my shirt after saying I was hot. I want to tell people, but he has a promising future, having his mind set on becoming a pilot and knowing how to fly a plane ever since he was 13. And here I am, venting on Reddit. I don’t want to ruin his reputation knowing I couldn’t do anything half as good as him. And what’s worse, he isn’t even a bad brother. He’s just a bad person in general. I’ve tried every excuse to ease my mind, ranging from telling myself it was an accident to him being asleep whilst in the act. The most logical explanation I can come to is he swas going through withdrawal from the drugs he took not that long ago. I want to tell, but my family’s birthdays are scattered, meaning every month had atleast one birthday or holiday and I didn’t want to ruin that. And I don’t have any friends to vent to. Any advice would help.