CBP is completely inconsistent with how they treat these situations.

Before we were married we would fill out 2 customs forms and approach together. We had a series of CBP officers that would tear up one of the forms and tell us that we only needed to fill out one as we lived together and were clearing customs as a unit.

So we started to fill out one form. No problems for a couple of years. Eventually we came upon an agent at LAX who took offense to this and sent us back to fill out a 2nd. When we arrived back at the same agent with 2 forms, I mentioned that CBP has never asked us to fill out 2 forms before and have been told to fill out 1 and not 2 in the past. The funny thing is that we had cleared the exact same CBP facility (LAX TBIT) weeks earlier with 1 form. He lectured me that he has been doing his job for many years and that I "must be mistaken".

CBP needs to make a policy one way or the other and follow it, not leave it up to the whims of the officer.

Global Entry is a huge stress relief.