With the spreading issues of narcissism and codependency, it has become common for marriage to mean enmeshment. The narcissist expects it with them being the dominant figure. The codependent expects it with them being the submissive figure.
What does this look like from the codependent? A person who is more codependent will sacrifice who they are to keep those around them happy. They sacrifice their own hobbies, desires, needs, and boundaries. They feel happy and secure when they are able to meet the other person’s needs. Thus their entire identity revolves around the feelings of the other person.
What does this look like from the covert narcissist? A person who is covert narcissistic will not make any sacrifices for the happiness of those around them. They feel happy and secure when others are able to meet their needs. So they encourage this, and even demand it. They want everyone’s focus to always be on them. Thus their entire identity revolves around themselves.
Marriage is not supposed to be an enmeshment. You don’t have to do everything together. In fact, I recommend that you don’t. You have your likes and dislikes, and they have theirs. You have your hobbies, and they have theirs. It is okay to do some things together, but each of you still has your own personality and desires. It is vitally important to both parties that marriage not become an enmeshment.