Today my 4 year old son drew a sketch of our family where he has shown his mother's breasts very elaborately. I was shocked to see his observation at such a young age. Should I do something or ignore?

I gather this might be his first time doing this? Given his young age and ongoing learning process, it's important not to overly worry about it. Should you find yourself feeling quite uneasy and if this behavior recurs, consider having a gentle conversation with him about it. And I hope you shared a hearty laugh with your wife over the situation :D https://www.budgetingenterprise.com/