As long as he's not treating people like he treats Alec because he's afraid that Alec might turn him into unnatural. And instead treating people like Alec because... it's a nice way to interact with them? Or something. Because they're usually not looking for a fight.

"Spirits, children, adults. People," Alec says with a grin and wave of his hand. No, the spirit isn't very tasty unless one likes the taste of fire.

Alec rightly deserves to get mocked and appreciates the fact that Zack is trying not to. "One. But one is more than enough."