"And above all things have fervent charity among yourselves: for charity shall cover the multitude of sins." - 1 Peter 4:8
The deepest love between a husband and wife keeps no record of wrongs. This love is the love that covers a multitude of sins - not because the sins never happened, but because they are covered, and washed away by love.
Keeping no record of wrongs isn't natural - it is a choice that must be made. Keeping no record of wrongs is choosing to not hold someone's sin against them! A love that keeps no record of wrongs will not harbor any bitterness against you for your mistakes, nor will you be loved less because you are fallible. This is unconditional love, a love that endures forever, even through the mistakes we make.
This is like the love that Christ showed the Church! He loved us in spite of our sins, and through His love we are transformed, and so we should also love each other unconditionally and give each other the grace that we've been given.
Brianna and I have found that as we refuse to hold our mistakes against each other, we become more one - because there is no part of our hearts that we have to hide from each other. Our love becomes deeper and more real, because it is unconditional, and nothing can take it away.