Yes, this is completely normal and it sounds like (if you haven't already) it is time to have a talk with him about sex. If you have a trusted male companion or relative might not hurt for them to have a talk either.
Good Question!!! Even though I don't have a son, I know lots about children. The reason why your son is looking at you is because he is "wondering" and "curious" about a woman's body. Its not so much as he's looking at his "mom", he just knows that his mom is a female and that she has the same body parts as "girls".
Ask him questions, in a nice kinda, playful, motherly, curious way, do you wonder what a woman's body look like? Breast and a body part that men, or boys don't have, so it makes them curious as what they do, what they feel like, what part does the nipple play on the breast. Trust me mom, its NOT about you. lol its about the part of the body that "they" don't have....and want to learn more about.
It may even turn him on to see you undress, its all in learning for him. We as parents already know about parts of the body, and life in general, you son is just learning. So be willing to share with him and COMMUNICATE with him about it.
At least your son is not running for a porn video or photos of naked women. You have him in postion where you can teach him RIGHT AT HOME! So that when he sees a womans body else where, he wont have to stare and wonder, he will already know.
And when you talk to him, be sure you include the issues of privacy and respect. And keep your door closed. Lock it if you have to.
Yes it's time for that talk and to tell him that it is not the "right thing" to do. I love the talk about privacy and respect too. It's a tough one! I hope your son will stop once you talk about it.
Other people asked questions on similar topics, check out the answers they received:
Other people asked questions on various topics, and are still waiting for answer. Would be great if you can take a sec and answer them