So I just found out last night that a couple of my FI friends who are getting "married" at the end of the month in Mexico are already married. They didn't want to go through the hassle of all the paperwork to get married in Mexico. They are having 30 people fly down there to watch them get married including lots of our mutual friends and a guy who works for my FI. I know that nobody else knows that they are married already and are spending over $3000 to attend this wedding. Should I tell our friends that they are already married or is it none of my business?