Trey comes to town in June 2012 as the producer for Kristina Corinthos-Davis's reality show, Mob Princess. He immediately clashes with Kristina's parents, Sonny Corinthos and Alexis Davis, who believe he is exploiting Kristina. The premise of the show is to provide an intimate look into the lives of Kristina and her family, particularly her father and his relationship with Kristina. Alexis threatens to sue Trey over the show, but Kristina uses emotional blackmail to get her parents' consent. Kristina starts to see the harm in the show when Trey ordered the cameramen to film Kristina in the hospital with a grieving Sam after the death of her son. And when they caught Molly with her secret boyfriend TJ.
In July 2012. Trey is seen making a phone call to his father, who is funding the production of Mob Princess. When Joe Scully Jr. is arrested for murdering John McBain's sister, Theresa and raping Kate Howard (who Joe knew as Connie Falconeri), Trey goes to visit him in jail, and it is revealed that Joe Jr. is Trey's father. Joe Jr. asks Trey to help him take down Sonny using Kristina. Trey returns to Port Charles and tells Kristina he is scrapping the reality show so they can be together.
Trey cons Kristina into marrying him, and they take off to Las Vegas, followed by Kristina's brother, Michael and his girlfriend (Trey's roommate), Starr Manning. They try to tell Kristina about Trey's misdeeds, but Trey tells them that he made it up as a storyline for the show. Back in Port Charles, Sonny and Alexis are livid and try to have the marriage annulled. Kristina rejects the idea, stating that they've already consummated the marriage. However, when she learns the truth about Trey and his father, she demands the marriage be annulled.
In early October, after her fight with Trey, Kristina is kidnapped by Joe Jr. and taken to Sonny's warehouse. Trey finds her being held at gunpoint by his father. He begs Joe Jr. to let Kristina go and they struggle over the gun. Joe Jr. gets shot in the shoulder and takes off. He was patched up by Cesar Faison, disguised as Duke Lavery. On October 23, Joe Jr. goes to the Quartermaine mansion after being shot by Jason Morgan. Trey arrives in time to say goodbye to his father who dies in his arms.
In late November, Kristina sees Trey working at St. Timothy's Church after Edward Quartermaine's funeral. He works there in exchange for food and a place to stay. At Kelly's, Trey tells her there are no jobs for him and considers leaving town. On December 12, Trey tells Kristina he is going to work for David Vickers in one of his productions, and invites her to go with him to Los Angeles. Kristina accepts his offer, and her parents reluctantly consent.
After Trey and Kristina tell Connie that they are leaving town, she drives away and they follow her with Starr and Michael. The car crashed and all four occupants are unconscious. Connie and Spinelli's girlfriend, Ellie Trout are also in the accident. On January 8, Dr. Patrick Drake meets with Connie, Kristina, Sonny, Starr and Michael about Trey's condition. Trey had an aneurysm (blood-filled balloon-like bulge that is deadly if it ruptures). The aneurysm ruptured, and Trey is declared brain dead. As his next of kin, Connie decides if and when Trey is pulled from life support.
On January 14, 2013, Connie then realizes that she should be there for Trey when he is taken off life support. Later on, the doctors turn off life support and Trey passes away.