Access the Facebook website, and log in to your online account. Your News Feed is displayed when you log in.
Click "Edit My Profile," and select "Featured People" from the side panel.
Click the "Relationship Status" drop-down list, and select "In a Relationship."
Enter your significant other's name in the next field, and click "Save Changes." If the person is a Facebook friend, a request is sent to him to confirm your relationship. The person's name will appear as being in a relationship with you, but a link to his profile is not provided until the relationship is confirmed.