I was written to the other day by a mother of a 2.5 years old who was wondering how to approach talking about her pregnancy and the arrival of a sister into the family with her son.

So first we need to think about what language has been used around him in terms of body parts. Using the scientific words for body parts is one of the fundamentals of good sex ed to empower children. So make sure you are using ‘penis/testicles’ and not nicknames, and if you are, just explain we are going to start using the proper words from now on. Children are very accepting and just repeat the correct terminology back to him if he continues to use old terms that he has learnt previously until he doesn’t any more. PS. The more family members that are on board with this, the better!

🤰 When talking about the baby, if you are not doing so already, use the word uterus rather than tummy for where the baby is.
👶Obviously once the baby has arrived, changing nappies and bath times are times where he might talk about the differences he’s seeing. I think keeping things organic whereby you are responding to him and what he is looking at/pointing out or saying is key and repetition often really helps.
📚 In terms of preparing him, you could start sharing some age appropriate books with him where you can already introduce body parts, for example, “your sister will have a vulva (PLEASE USE VULVA RATHER THAN VAGINA 😊)like mummy, you have a penis like daddy.”(If that’s the case in this particular household).
😔The shame/stigma for these words comes from adults and not children so the more comfortable we are using the words, the more we model that there is nothing to feel ashamed of or secretive about when it comes to private parts.
📖 A good book for you to reference and then have in the house to dip in and out of is ‘Let’s Talk.’ 
🤱Once baby is here, if he goes to touch her body/hug her etc you can already introduce consent just by simply saying, “can I hug you?” Start as you mean to go on and that will become a natural part of their behaviour and is excellent modelling of consent and bodily autonomy. There are always opportunities at this age to teach consent.