Thank you for using Just Answer. It sounds as if he is generally curious about the difference in you and he. Some children begin this curiosity early, and it is very important to be as honest with him as possible. Using the true names for breasts or genitals, etc.
I am not sure if he is exposed to other females such as his age group, but this may be arousing his curiosity about how and why you are different from them.
Many children can relate to an honest discussion about good touch and bad touch as it relates to them, and also as it relates to you. Making him aware of how boys and girls are different and the need to respect each others privacy and body parts is important. A rational discussion of the differences may help.
One thing I did with my child when young was when I realized she had questions about certain things, I would give her 10 minutes of reprieve. During this time, she could ask me anything in the world, and I would always be honest with her, and there would be no punishments for her if she used a bad word or said the wrong thing, etc. We also agreed that once that 10 minute period was over, we never discussed it again, unless she brought it up. I did this periodically through out her life and as she got older. It was during this time that she asked me about sex, certain words she had heard, dating, etc. It really made our relationship better, and let her know I would be honest with her, and she could be honest with me without punishment.
When it comes to sexuality, the taboo of it is what makes children so curious. Taking the taboo away by being honest and direct, makes it just another learning opportunity.
Your son is in a natural curiosity age, so be as direct and calm with him about this sensitive issue as possible.
Please let me know what questions you have. Gina