Physical Relationship Education.
Sex education is complicated. It's about procreation, right? The mechanics, the biology. But it should also consider a variety of sexualities, a variety of genders, a variety of activities aside from intercourse. It involves learning about risks and, maybe the most uncomfortable topic in some conversations, pleasures.
It should be all of this, because when it's not... well, over and over we see that when it's not, people don't stop doing all the things - they just do all the things without the knowledge of how to do so in healthy ways.
That said, is there a time and place for what we call sex education? Sure. No three-year-old is capable of understanding anything about sexual behavior, from the mechanics to the emotional implications. This is why sex ed is often tackled near puberty, when it becomes a timely topic for their physical and emotional development - and even then the information should be imparted with care, because it's big stuff.
But with all that sex ed encompasses, it does make sense to start early in that, at its core, it's just about physical relationships, and those begin at birth.
Imagine two children:
One is taught, even as a baby, to respect physical boundaries. Biting, hitting, or other agressive actions are not ok, and as they grow they learn that hurtful or disprespectful words are not ok. This kid is encouraged to understand their body parts and they have healthy models of both body confidence and a sense of privacy. Information about bodies and, eventually, relationships is given with candor and without shame as appropriate for their unique personality.
Another kid is never given real names for their body parts and, in fact, is not allowed to talk about them, let alone draw attention to or touch them. They probably learn that biting and hitting isn't ok, but beyond that there's no example of how to respect anyone's body, even their own, because the topic is simply off the table. The lack of those conversations leave this kid to conclude that bodies are taboo - maybe a joke, maybe gross, maybe shameful. They don't develop a sense of how their words and actions might affect another person's physical or emotional security.
These scenarios are pretty extreme, especially the latter, but they show how early exposure to some of the concepts sex ed will cover is absolutely ok. Which of these kids do you think is going to have an easier time learning about the more provocative topics? Which one will have an easier time navigating an eventual physical relationship? Make that any relationship?
Sex ed can - and should - begin very early, at the appropriate level. It will all become relevant when the topic of sexual behavior does enter a kid's consciousness. If calling it sex ed makes you uncomfortable, call it physical relationship ed.