Why would you be asked about where your wife is? Most people on this board would probably say "home, waiting for me" or "home with the kids".
I don't think there's an obligation to go through the same line when traveling with your partner. I see it more like a convenience.
HTB.
You would be surprised to hear about some of the creative questions they come up when trying to asert if I am going to stay illegally or not. Let's just say that being married to an US citizen and not being a US resident......they think I am either a) Crazy b) Ready to stay illegally
If I was an immigration officer and someone would tell me that a couple travelling together cleared separately.......even I would be suspicious