I'm curious as to how you know about this, assuming that you are not either Sam, Jazz, or one of the other four people in attendance at the ceremony.
If you are not, then the secret's out anyway, right?
If you are, then I'm guessing that you are not comfortable with keeping this secret.
If this IS the case, I'm not sure how obligated you are to comply, but on the other hand, I'm not sure what good would come if you didn't.
One of the sisters that was in attendance is my granddaughter-in-law. I don't know why she told us (her DH's family), but we know both Sam and Jazz to varying extents as Jazz lived with sis while my grandson was deployed and Sam eventually moved in, too. I"ve spent time with them all, including a week where everyone was ill and they needed help with the kids (my great-grandchildren).
I guess the secret IS out. I don't know who all might know, but someone in Sam's family asked a question about it, and she lied to them.
I am completely comfortable keeping the secret because it doesn't matter one way or another to me and I get it with the military aspect. I know that revealing the truth would cause upheaval and hard feelings and, as an in-law, I wouldn't want to do that.