When you are giving your baby a bath, name all of the body parts as you wash them. (day2dayparenting.com)
Encouraging Body Autonomy: * Teach your child the correct names of their body parts, that their body belongs to them, and that they control who touches it. (mothermag.com)
You can ease into the discussion with proper names of body parts and what their main job is (sperm is produced in the testicles, eggs are stored in a woman's ovaries, the uterus is where the baby will grow...) look up anything you have a question about before starting your discussion. (motherscircle.net)