Successfully complete the Burning Desire mission where you rescue Denise. A red two player free roam icon will now appear on Denise's porch near the door. The icon will appear there when she is home and will go on a date. Note: If both enter a car, the passenger will have free aim with a machine gun. Do not try to kill Denise, because you will never be able to date her again or play in two player mode at her house. Additionally, once you get your girlfriend, take her on a date. After you drop her off, there will be a rotating icon of two people directly in front of the door. Walk into it. It will tell you to push any button on the controller two. Do so to start two player mode, involving CJ and his girlfriend in a free roam. For more fun in two player mode, start the two player mission. Then, enable the "Spawn Jetpack" code and remove the Jetpack. Then, have player two get the Jetpack. Enable the Jetpack code again, then have player one get it. Both players can now fly around and do the two player missions this way.