“The process of talking about sex should start before they’re verbal,” says Silverberg. That means incorporating the proper names for genitals into everyday activities like bath time. While Silverberg isn’t against also using cutesy names, “Penis, vulva, vagina, clitoris, bum and nipples are all terms that every toddler should know,” he says, explaining that they need these words to communicate health issues or injuries.
Teaching your baby the anatomically correct terms for her genitals might sound daunting, but Thornhill says to be casual and treat those terms as you would the word “arm” or “ankle.” She also recommends avoiding connecting sexual biology to gender. For example, drop the idea that all boys have penises and all girls have vaginas. Instead say, “People with penises” or “People with vaginas.” Thornhill explains that by watching your language now, you set the groundwork for easier conversations about gender roles and identities later.
Closer to age two, you can start talking to your kids about when and where it’s appropriate to explore their bodies. If your toddler has the tendency to touch his genitals-which is perfectly normal-use it as an opportunity to explain how that’s something we do in the privacy of our bedrooms. “You want to be really gentle,” Thornhill says, explaining that you don’t want your child to feel like he’s doing something shameful.
A major focus for this age group is learning about boundaries and what is and isn’t appropriate when it comes to touching-or being 
touched-by other people. “This is fundamental to consent,” says Silverberg who explains that it’s crucial that even young children learn to ask before they touch someone else. Lessons around sharing, touch-based games like tickling, and asserting your own boundaries, such as telling a child when it is and isn’t OK to climb onto your lap, all help to create a more intuitive understanding of consent.
While you can skip the explicit details, now is when you should be telling your child that others should never ask to or try to touch their genitals
Establishing that kids have a say over their own bodies also helps with keeping them safe. Thornhill says it’s important to convey that your kids can tell you about inappropriate actions at any time, even if they’ve previously kept it a secret.
Instead, discuss how it’s not appropriate to handle other people’s genitals, as these are very special parts of the body that shouldn’t be touched by others
At this age, kids can be very curious about each other’s bodies. Thornhill explains that it’s important to acknowledge this inquisitiveness and use it as an entry point to discuss your family’s rules and values. “Talk to them explicitly about when it’s appropriate to be naked,” she says. And if you do catch your kids playing doctor, don’t freak out.
At this age, your child might begin asking how babies are made. For Silverberg, the easiest and most inclusive answer is, “There are lots of ways.” The author, whose first book What Makes a Baby answers this question for the preschool set, explains, “The amount of detail one goes into really depends on how much you think your child can comprehend.” If your child wants more information, you might try something like, “Two grown-ups get their bodies together and share the sperm and the egg to make a child like you, or sometimes they get the sperm or egg from someone else.” Silverberg adds that it’s fine to tell your child that some details, like how sperm and egg meet, will be discussed later. “It’s just important not to lie.” He adds that it’s important to actually follow up with those questions and not just refuse to talk about certain things.