Sai de Silva's husband wants out of their marriage ... filing for divorce about 9 years after the two tied the knot ... TMZ has learned.

David Craig filed for divorce in New York City Thursday morning, according to court records.

Sai and David met in Costa Rica back in 2009 while she was vacationing and he was on a business trip. Sai says she was pretty hungover when they met ... but he made her laugh and got her attention.

They welcomed two children -- daughter London in 2011 and son Rio in 2017 -- together before saying their "I do's" in 2017.

While Sai isn't shy around the spotlight, David reportedly likes his privacy ... rarely popping up on his better half's social media over the years. That said, SDS has made it clear David is a very involved father ... and he has appeared on 'RHONY' occasionally.

"The Real Housewives of New York" -- which De Silva joined before the 14th season as part of a major cast shakeup -- is currently shooting season 16 ... so, we imagine fans will get a chance to watch all the action when it hits the airwaves eventually.

We've reached out to Sai ... so far, no word back.