Got Milk?

Explaining pregnancy and birth to a three year old has been relatively easy until I got to the part about how all mamas are able to feed their babies. We studied cows and dogs for instance and I showed him pictures of what it looked like. When he found out that we get our "people milk" from cows he wanted to know why milk from all the other animals wasn't in the grocery store too?
Well, once we convinced him that:
1. No, unfortunately I wouldn't be able to feed the other animal's babies and
2. Even though it may look (and feel) like the breast pump is violently sucking your "napples" down a clear tube, I will in fact, be keeping them attached to my body, he suddenly became very interested in my breast pump.
One night after Tim had given John Carter his bath and put him on our bed while he got his PJ's he came back in the bedroom to find this:


John Carter is buck naked, sitting on our bed watching Sponge Bob while he "pumps."
...and by the way, he said when he pumps, his milk is always pink...