If you are, you might want to check to see what kind of foundation your marriage is being built on. Common courtesy requires active, attentive listening. Good manners require civilized language. Common courtesy requires thoughtful attention. Good manners require us to consider how our words and attitude affect others, and to make adjustments as needed.
Common courtesy requires thinking of someone else's comfort, wants, and needs first.
Good manners require the discipline of mature behavior. Common courtesy requires putting one's best foot forward, especially in the one relationship that means the most to us. It's hard work to consistently practice good manners and common courtesy. And sometimes we don't feel like taking care or making the effort. If we persevere, though, and practice courtesy and good manners toward each other on an every-day basis, those qualities will become a natural part of our relationship.