Sounds like you need to call a tax attorney. Is this house in a country that is not your own? Or is the buyer from another country?

Buyer is from another country I guess. But my realtors wife chatted with them when we were viewing the house and they said they were moving back to Boston.

Ok so Google is my friend. Just searched the question and found a handy page that spelled it out real simple, thank you title junction! So long as we make sure the 10% of the sale is paid to the U.S. for taxes there shouldn't be an issue. Wish more sites I've googled were that easy to understand LOL

I'll double check with an attorney or IRS person, but it appears from the rules the house we are looking at will be under $300k so should just have to sign a document stating that along with that it'll be a primary residence and I think we'll be in the clear.