Instructions
See how much a certain character likes you by targeting them and pressing the left trigger button the Xbox controller. A bar will appear at the top of the screen displaying your current status with the character.
Perform expressions to gain favor with the character, such as flirting or giving gifts. When you have gained enough favor for them to fall in love with you, a heart will appear above their head. A character has become a potential spouse when you see a ring on their status bar.
Propose to the character by giving them an engagement ring, which can be bought from a trader. If the potential spouse is wealthy, you will need to give them a more expensive ring to please them.
Lead your potential spouse to your home or purchase one if you do not own one. When looking at the deed, select the option to "Set Marital Home." This will complete the marriage.