Facebook allows users to display their relationship status on their profile. In order to be in a relationship on Facebook, however, a relationship request needs to be sent from one party to the other. Once the request is accepted, the new relationship status will be posted to both profiles.
Log into your Facebook account.
Click on the "Edit Profile" button to the right of your name.
Click on "Featured People" in the left-hand navigation bar. Underneath where it says "Relationship status," there will be a picture of the person with whom you requested to be in a relationship. If they have not yet accepted the request, it will say "Relationship request already pending." If they have accepted the request, it will say "In a relationship," or whatever your relationship status is (married, engaged, etc.) with the person whom you requested. Click "Save Changes" to save any changes you may have made.