Having made every mistake possible in marriage, I can speak on this subject from a position of humility. If you want to enjoy a secure marriage, remember: Both parties need to KNOW that the other has no plans on giving up on the marriage.
I am talking to mature, level-headed people here. If you have a sound (non-abusive) relationship then take it up a notch. Let your partner know you aren’t going anywhere. Guys can be just as insecure as Gals, we just hide it better. So this strategy benefits everyone.
We tend to be more honest when we know the stakes aren’t so high. In the long run, we all want to stay together. So just commit to it and get divorce off the table. Whatever leverage you think divorce might give you will pale beside the unity you enjoy. Understand, this means when one partner stumbles, they have no excuse to lie. Deal with whatever sin exists, knowing you are committed to doing it together
So come together, celebrate the marriage you have and put the commitment on paper.