Book on facts of life for nearly 8 year old

[mumtoone]

DS is starting to ask questions about the facts of life. I would like to get him a book that would help answer his questions (with my support). Is there anything suitable for a boy who is coming up for 8?

When dd was smaller we had a book called How did I begin which might be a good starting point.

Going into a bit more depth this book often gets positive mentions on here. We've got the slightly older version (Lets talk about sex) and it is very well written and comprehensive but definitely aimed at 9 or 10 plus.

The Usborne books are good imo. DD has the pink version but there is a lso a boy's version.