I’m 52. No couples at my junior school. It was Catholic though, so probably had a bearing.
My youngest is 11. Zero mention of couples at his Year 6 either (not Catholic).
However he’s just started secondary, and still thinks girls are annoying, but has said several of his classmates have girlfriends.
My 13 year old in Year 9 went through a bi debacle earlier this year. Her best friend since Infant school and decided she was gay and the two of them became a couple. They never met up or spoke during the whole lockdown, and now don’t even text. They’re at different schools.
After a long country walk when I sensed my daughter wanted to resolve this, she opened up that she wasn’t gay, she just didn’t want to lose her best friend. She said that ‘lots’ of kids are gay or bi because it’s cool.
She does have one friend who is definitely gay, known him since little figured he would be later. But even he’s ‘decided to try being trans and if he doesn’t like it he’ll turn back’, said my daughter.
Someone said before on MN, being straight and white in school these days is highly not cool.