@Marco ********
,
okay so let's recap. You have a year-long, multi-entry Non-Immigrant Type O visa based on marriage and you are on the FIRST 90 day entry from that visa.
AND
Rather than border bounce when this 90 days is coming up (so you get a new 90 day stamp) you want to get an extension so you don't need to bounce on that date? Correct?
As people said, you could apply to get a 60 day visit thai family extension. This entails you taking the correct documentation AND your thai wife to the immigration office and applying for the extension.
Keep in mind SOME offices allow this 60 day visit family extension once per ENTRY (meaning you could get the 60 day extension on every 90 day entry you make off that Non-O visa)
BUT
SOME immigration offices allow the 60 day extension once per VISA <- meaning you could get it ONE time on your year long visa.
I'd say don't waste the 60 day extension just because you don't wanna bounce out and back in.
AND I will add one more piece of advice, bounce now, there's nothing that makes you stay until the last day of the 90 day stamp you have now. NO reason to wait and bounce on christmas day :(
Good Luck,