What could be the consequences of a "Joke wedding" in a foreign country?

Question

Context :

Two of my friends, both French citizens, have a PACS. PACS is a form of civil union that can be "upgraded" to a marriage, but not "downgraded" from one.

They are planning a three weeks trip across California. They are also planning to get married under American law "for fun" during a week-end in Las Vegas, but won't do the paperwork to have this marriage recognized in France after their return.

My question :

What could be the consequences of this wedding?

For example, if they break up and end their PACS in France, would they still be officially married in the USA?

And if after that they marry other partners, could this be a problem for them when applying for an American visa?

Does France and the USA exchange information on wedding of foreign citizens on their soil? Could they even end up being officially married in France even without doing any paperwork themselves?

Answer 1

What could be the consequences of this wedding?

They would be married

For example, if they break up and end their PACS in France, would they still be officially married in the USA?

Yes, and also in France.

And if after that they marry other partners, could this be a problem for them when applying for an American visa?

Yes, bigamy is illegal in both the USA and France.

Does France and the USA exchange information on wedding of foreign citizens on their soil?

Don't know, probably not.

Could they even end up being officially married in France even without doing any paperwork themselves?

Most definitely. France recognises US marriages so they would be married in France (and the U.K., and Australia, and Germany, and ...). This is true even if the French government doesn't know they are married.