I had some friends do the same thing. The back story is that they had already set a wedding date, but needed to be married for something like a better loan rate or better insurance rate - can't recall which. They got married and swore everyone who knew to secrecy so that the parents wouldn't get mad.
Funny thing is that no one noticed that the official "signing of the marriage certificate" ceremony after the church wedding didn't occur. Kinda cool trick.
If the people who came to you only got married for a discount, well, that's insane. If they were going to get married anyway, well, that's solid financial planning
