Emotionally this one might tug at us because of what's going on in the country as pertains to marriage.
But remove the emotion and we are still called to obey the authority that is over us as long as they aren't asking you to do something in opposition to God. Thus a couple IN THE CHURCH should seek whatever formal governmental recognition is available for the sake of not breeding confusion.
By their example. could one rightly justify to two 16 year olds why they aren't married and free to have sex with one another or why two 30 somethings who have chosen to shack up and have sex aren't married just because they say they are committed?
If we start picking and choosing what we are not going to obey based upon emotion rather than Scripture, then no one need listen to anything we say Scripture commands.
We don't live in accordance to what the government is doing.
NOTE: also consider the context of what I'm saying here. This isn't a young couple shacked just having relations. They are a working and functioning family who just doesn't want Uncle Sam involved in their " relationship". I personally have witnessed good fruits produced by them. I by no means am endorsing shacking up but in a situation where the INTENT in genuine I have mixed emotions
None of the above matters. Obedience is better than sacrifice. If they have not done what the authorities over them require, then they are being disobedient and giving the appearance of evil and breeding confusion that is not of God.
Why did he tell you that he wasn't LEGALLY married?