I got married right at the end of the year, to a UK citizen. I've lived in the UK for a long time now; I report my UK income (and then exclude it via 2555) as well as some US self-employment income. My wife worked for a US company until end of September; she returned to the UK several years ago and worked remotely for them. She never filed returns; as best I can tell, the company deducted the right amount of tax for her. She was on an "investor" visa (E2, I believe) -- no green card.
Now that we're married, the question is what status to use. If we file jointly, we both benefit for 2016. Can I continue to file jointly for future years, benefiting from the lower taxes while not reporting her UK income? That would be nice, but it seems like the kind of thing the IRS would want to prevent.
We could file jointly for 2016 but then separately for subsequent years -- but what that would mean in practice is that she won't do a return -- possibly a red flag of some sort.