Gerald was a demon, who along with Raul opened a brothel as a means of collecting souls. Because of the war with Abaddon, soul deals were down and so Raul and Gerald decided to take a different approach, entering the sex trade to bring numbers up.
When Gerald is arguing with Caitlin about her not wearing the clothes Raul picked for her, Raul tells Gerald to not "leave any marks." At that moment, Rowena walks in through the door, and tosses him a hex bag that appears to liquefy and violently purge the demon from its vessel, killing him. As Raul is dying, Gerald smokes out of his meatsuit and finds the nearest body to possess and reports to Crowley what has happened.
Gerald convinces Crowley that he should go after Rowena for the act of aggression. Later, Gerald reports to Crowley, saying that while the alpha team were killed by the Winchesters, the beta team caught Rowena as she was trying to escape. He takes Crowley to her cell, where she has been tortured and offers to gladly finish her off. An exasperated Crowley tells him he has nothing to be proud of about as this was Gerald and Raul's mess to begin with, and dismisses him.
After Gerald delivers Trish to the dungeon, he listens to Crowley talk about his mother -- interjecting that his mother burned him with cigarettes, which Crowley doesn't care about. Gerald then offers to kill Rowena for Crowley, telling him he would have no problem with it as he killed his own mother over the cigarettes. Crowley then has Gerald collect Rowena, after Crowley has a chat with his mother he and Gerald escort her to the dungeon. It's there that Rowena accuses Gerald of smuggling demons out of Hell, to which Trish confirms. Gerald denies the accusations, and begins to strangle Rowena. When he doesn't listen to Crowley's repeated orders to stop, Crowley stabs Gerald through the neck with an angel blade, killing him.