Parents should ideally be the first people to talk to their children about sex, and that time is as soon as their children can talk.
"Parents would be surprised to learn that by as young as age seven, children know a lot more about sex than we'd imagine or like them to."
Don't overcomplicate it, speak to them at the age they're at, in a language they understand and grow the conversation as they grow older.
They may at that age already be curiously asking you what sex is, where babies come from and why their private parts are different.
"So if you're not the first person to talk to them about it, their understanding of sex will be shaped by what they hear when they're playing with their friends, what they see on television or what they happen to come across in magazines," said intimacy coach Tracy Jacobs.
"Don't overcomplicate it, speak to them at the age they're at, in a language they understand and grow the conversation as they grow older," she suggested.
The "people's doctor", Dr Sindi van Zyl, also recently offered some tips for parents on Twitter:
Here are a few pointers to get you started:
1. Stress that sex is not shameful
Sex shouldn't be shrouded in secrecy, mystery, shame, guilt or dirtiness. "It's important that our kids know that sex is a good thing and was created for our pleasure, both men and women, and there is no shame with that," said Jacobs.
They can learn this through conversation with you, and your level of comfortability, tone and the manner you treat the sex subject will indicate to them whether or not it's okay to talk about sex.
"The moment we experience shame and guilt, we internalise it," said Jacobs, and this can easily happen to impressionable children.
2. Call private parts by their names
Jacobs, acknowledging that this may be challenging for parents who grew up in cultures where sex talk was taboo, and where private parts were referred to by other euphemisms, stressed the importance of calling a vagina a vagina, and a penis a penis. This helps decrease shame or shyness around that part of the body.
3. Talk to them about masturbation when the time's appropriate
"My grandmother taught me about self-pleasuring because she wanted me to know that that pleasure was from me," Pinkett-Smith said. "She didn't want me to fall into the hands of a man and if he gave me pleasure, to think that that was him."
"Again, if you don't talk about it, you risk them hearing or reading it from other sources, who can go about it in an unhealthily way," cautioned Jacobs.
4. Stress to girl children that sex is for them too
Education is crucial here as a great number of women grow up believing that sex is either for the pleasure of a man or for procreation. Something Pinkett-Smith also stressed. "We as women have been trained that women aren't supposed to enjoy sex, sex is not for women, sex is for men, pleasure is for men — and honestly I think that's why so many women that I know have never had orgasms," said Pinkett Smith.
"Women are healthy sexual beings and they must grow up knowing that they have a right to feel pleasure," said Jacobs.
5. Teach them about consent very early on
From very early on, teach them the difference between 'good touch' and 'bad touch' and what to do should the latter happen to them. Conversations about good touch should continue throughout every age and stage.
Also teach them about consent, that they have every right to say "no" to anyone who tries to touch their private parts against their wishes.
"You want to be an 'askable' parent," said Pepper Schwartz, a U.S. sociology professor and relationship expert.
"Your kid should know you love this kind of conversation. He's constantly forming pictures in his mind of what reality is — and they're not always accurate. You want to be there to give him the truth and assuage any worries."
Also, discussing all things sex and body-related with openness and honesty demonstrates to your child that he or she can approach you to talk throughout their growth, as they grow more curious and have more questions.