Just asking for somebody.....
- It's a HK person now in China.
- Stays in China with Home Permit right now
- Also has a US passport
- Wants to fly from China to the US, not via HK.
At check-in in China they want to see of course his US passport.
But how about at China immigration?
And what if - he is not supposed to have a 2nd passport, right? Will that be trouble?
Or can you use the auto-gates when you exit? In that case nobody would ask, right?