Well, the cat is out of the bag now! If he wanted to keep his life private, why blurt it out to you? Evidently, he can't keep his mouth shut and just had to tell you about his latest antic. If he did get married, I wish the two of them all the luck in the world...it is a match made in heaven because she's got to be a loco as he is.
I feel for your sons. They may have met her 14 months ago, but that doesn't mean that they knew she was his "real girlfriend".
I think I would wait a few days before saying anything to the boys. I would have a nice meal on the table, be sitting there eating and casually mention that you got an email from their father announcing his new marriage and then say, I wish them well. Then drop it. You don't want to ask them any questions about it, because they would then feel like you are trying to find out all of the dirt. If I know your sons, they will eventually come talk to you about it, but they need to do it on their timeline. They have to digest why their father said it was a secret and then announce it to you.
They know that their father isn't the sharpest knife in the drawer at the moment.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
