There are these little monsters, that can sneak into your home & wreck havoc on your marriage. I know one if called Bitterness; there is one called Offense-not-dealt-with. Misunderstanding is another one. There are more, but I can't think of their names right now.
I am pretty sure these guys will come poking their ugly heads into your house from time to time. BUT, don't let them stay. You've got to fight in order to keep your marriage monster-free.
They can be sly. You may be tempted to let them in the door. You may encourage them to stay a while. And then, you start to feed the monster...
Whatever you do, don't do that. Don't feed the monsters. They won't leave you alone. They'll follow you everywhere. The monsters will follow you to bed. They may hide under your bed. Although, they will most likely get right into your bed and sleep right in the middle, all night long.
The longer they stay, the harder it is to get rid of them. They may tell you that no one else will notice they are there, and that they won't do any harm or be any trouble. None of that is true. Don't believe them! They will rob your marriage of intimacy & peace & joy.
Consider these truths about love from 1 Corinthians 13 -
"...Love is not provoked, it does not take into account a wrong suffered..."
Ephesians 5 offers a lot of relationship wisdom.
verse 26 says "Do not let the sun go down on your anger."
If there is something ugly between you & your spouse, deal with it. Maybe it has only been there for a day, maybe a week, maybe 5 years. It doesn't matter who started the ugliness. Go & deal with it & restore your fellowship. I think things will get a little sweeter.