It’s an important conversation. It’s also one that’s relevant outside of sex. Make sure to have the talk with your kids. Young kids. Preschool kids and toddlers.
How would you possibly go about doing that? Easy.
“Timmy, you don’t touch people without asking first.”
“Remember, no one is allowed to touch you without your permission.”
“You don’t have to give Grandma/Grandpa/whoever a hug and kiss if you don’t want to.”
See how easy that is? Any kid can understand that. Teach your kids to respect consent and boundaries when they’re young and when it’s time to have the sex talk when they’re older, the consent stuff will seem like common sense to them.