I often hear that a marriage is just a union of two sinners. How true that statement is!
Romans 3:10 tells us that, "There is none righteous, no not one."
None of us are perfect. Just as we receive forgiveness from Christ, we want to receive forgiveness from our spouse. If we want our spouse to forgive us, then we must offer our spouse our forgiveness.
And be ye kind one to another, tenderhearted, forgiving one another, even as God for Christ's sake hath forgiven you.