Marriage might require consummation, but procreation doesn't require marriage.
Exactly.
I wasn't clear - it was a young children's sex education book. I found it among the shelves at home while being nosey - either my parents were intending to have The Talk at some point, or they figured that by the time I was old enough to find and read the book, I would be able to deal with it myself :)
What it described was a man and woman laying very close together and the man putting his penis inside her vagina
But on top of that, I forget exactly how it was phrased, but it was clear that a necessary precursor to this was for them to be married, which I struggled with. Given the biological description, it seemed like there must be a biological reason, which didn't make much sense to me.
I wasn't yet old enough to figure out that a biological text might include religious lies or omissions, trying to assuage sensibilities, so struggled with trying to make sense of the simpler explanation that marriage was a official ceremony for some biological procedure people didn't talk about. (Like some sort of circumcision type thing to make one of the parties able to procreate?)