Cute! That is definitely a skunk. I think they are pretty unmistakable, it's hard to confuse that with a cat or a ferret.
They don't have to be de-scented to be tame. I've touched/handled plenty of wild skunks before, especially young ones, and as long as they are not frightened or threatened they will not spray. It's possible a neighbor has fed it or it was an orphan raised by a human, but who knows? We had a female skunk nesting under my family's house when I was young and the baby skunks would come out in the yard and play with our cats, and I even picked them up to pet them.
Skunks in a pet store? I did not know you were really allowed to keep them anymore without a special permit. I wanted one for a while, but could not find a supplier of already domestic ones, or a vet willing to de-scent and neuter a wild-caught one. They all told me it was illegal to keep them now.
I would keep an eye on him, though, and be sure he's not eating your eggs!
Strange things can happen sometimes. I saw a video once of a tiger nursing piglets.