Yeah, I've experienced a bit of that.
There was this one guy in one of my classes and we always got paired up in a group because our surnames were next to each other on the roster. Eventually, about halfway through the school year, my teacher allowed for free seating and pairing up with people for projects. I usually paired up with the guy, he was nice, we got along (and he was also the only person I knew in that class). I explained my orientation to him, and he was accepting and didn't have any feelings towards me. Since we usually paired up the entire year, a couple of his friends and some "popular girls" started saying that "you two would look so cute together!!" and stuff like that. It just... made me really uncomfortable and I didn't understand the hype around romance and having a relationship. My classmate, knowing I was aroace, tried to get his friends to lay off but they just kept making side remarks about it. Eventually we stopped pairing up to stop this, and I started joining a group with a different friend of mine who had transferred into my class. I'm still friends with the dude, we just don't pair up in class unless required by the teacher.
So yeah, idk why romance is such a big thing at schools but i can totally get where you're coming from.