Where Do Babies Come From?

So I was watching a T.V. show where one of the individuals is pregnant and this particular episode was showing the ultrasound and the following is a conversation I had with my son:

Gabriel: Is that a baby in there?

Me: Yes

Gabriel: How does the baby get out? Through the belly button?

Me: Ummm Yes that is exactly how it happens!

Gabriel: I bet I was hard to get out.

Me: Well I did it.

Gabriel: Wait a minute how come I have a belly button if I'm not allowed to have a baby!?

Me: Ummmm ..Well that is also how I fed you when you where in my belly.

Gabriel: That's weird!

And he runs off to his room, probably to convince his older brother where babies come from. I really hope I don't have to have this conversation again with Darian because something tells me he won't be falling for the belly button story.