There are many reasons to dress down when in a relationship, but staying that way all the time is not good. Keeping up a stylish wardrobe in the latest fashions is less important than dressing with care, and it shows in self-esteem. A partner who lets their wardrobe devolve into mismatches rags might begin to see a change in the attitude of their partner, and they might lose respect for each other if the trend continues.
When a couple has been together for a while, they might relax and enjoy wearing casual clothes. There is nothing wrong with this, and there are many reasons to dress this way. If they have small children, they might start the day out in a matching outfit that looks great. By the end of the day, they might have added a layer or two of dirt, baby food or even finger paint. This is not the way most people want to look, but it is a reason to keep the good clothes in the closet.
Doing projects together often requires a couple to dress in their worst clothes, and they will be glad they did when the work gets going. Remodeling a room or refinishing furniture can be messy, and it is best to wear clothing that means nothing special. At the end of the project, the clothes can be discarded if it becomes necessary. The couple will not lose respect for each other, and their successful project might boost their esteem.
Dressing badly for certain days or events is acceptable, but dressing nicely is also important. When a person takes the time to dress well, they boost their own esteem, and their partner can sense the change. Looking at them makes their partner realize how special they are, and it gives the couple a reason to celebrate even a regular day together.