"Oh, we just know each other well enough. Like I said, there are differences."
Oh dear, how to explain a homunculus to a normal. "It's... a created human, of sorts. Someone tries to resurrect someone using alchemy and it creates a homunculus instead of a full human. How much of a person they are depends on how brainwashed they are, though. My alternate's still got his humanity, but someone like say, Envy? Total douchebag. Don't mess with him if you see him."
LOL IRONY.
"And the hand's mechanical. I lost my arm in an accident when I was little, and I got it replaced."