Transcript of the above video:

Do you want to know the easiest way to cancel a K-1 Visa application in terms of it being processed? Get married, because if you get married, you are not a fiancée anymore, you are not seeking the entrance of a fiancé to the United States. Therefore, you are no longer eligible for a K-1 Fiancée Visa. 

I know that seems simplistic but yeah this is something that does pop up from time to time as people don't think about it. They file for a Fiancée Visa and then they get married. People need to remember that a Fiancée Visa is for fiancées. A Marriage Visa like an IR-1 or a CR-1 or even a K-3 Non-Immigrant supplemental type of Visa, those are for married people but Fiancée Visas are specifically for fiancées. Getting married before arrival in the United States in K-1 status will result in the nullification of either the visa application or the Visa itself. If for example there was a fact pattern where somebody was issued a K-1 Visa and they hadn't used it to go to the United States yet, but they went ahead and got married abroad and then tried to use it, technically speaking that Visa is no longer valid and no longer available because it was meant for somebody who was a fiancée. 

So the thing to take away from this video and the thing to fundamentally understand is yes, American citizens can petition for fiancées to come to the United States for the sole purpose of getting married in the United States and then adjusting to Lawful Permanent Residence i.e. Green Card status. But if a person gets married prior to the adjudication and the conclusion and issuance and entry into the United States in K-1 Visa status, if they get married beforehand it will nullify that travel document; it would nullify the application or the petition for that same travel document, so basically it's not a good idea.

If you want to get married, go ahead and do so but seek a Marriage Visa; if you are wanting to process as a fiancée, process on a Fiancée Visa.