@noam USAn here. In elementary school, K-5, we always gave Valentine's cards to the entire class. I grew up in Alaska with several different teachers in those grades. So I would say it had nothing to do with gay. It was just normal.
Thanks @sunlitrain
I can't say my memories from age 7 are perfect. What stuck with me was that when the teacher said a valentine was a friend, even then I was a bit surprised, because I guess I already knew it had a different meaning.
But yes, could be the two parts of the story are unrelated.
@noam Yeah, I think it's normal for it to be framed as for friends at that age. Even now, family and friends wish each other "Happy Valentine's Day" and give chocolates or other small gifts. In my circles it's not just for romantic partners.
Your dad sounds like he had an issue with that though.
@sunlitrain No, my father really didn't have an issue with it. He just spoke directly.
@noam Oh, good. I am glad. In your country, is Valentine's Day only for romantic partners?