I'm your hot girlfriend and I'm about to go on a fun night out with some of my girlfriends, leaving you at home all by yourself! But I know that you can't be trusted to not spend the entire night wanking your cock over porn, so I decide to lock your dick away in a steel chastity cage while I'm out! I encourage you to try the cage on, whilst humiliating you for being such a pathetic jerk addict that can't be trusted not to wank constantly! I then lock your cock up inside the cage and attach the keys to my necklace, so I can take them out with me, leaving you at home by yourself unable to even touch your cock! You have the best girlfriend...right?