Playboy was born in 1983 in North Holland, Liberty City. He was once very book smart as a child (in later years he would become sorely uneducated), but when he was 8 or 9 he became close to the neighborhood's biggest drug lord, Dwayne Forge, who took him in like a son and taught him how to sell drugs. Dwayne was arrested in 1993, when Trey was about 10, and Dwayne had reserved a penthouse in Northwood for him, as he became leader of the North Holland Hustlers. This is likely when he gained the nickname "Playboy X", as the building is located on Xenotime Street (Playboy refers to it as "X" in Blow Your Cover). Playboy was a small-time dealer, also robbing people for some time before taking over the gang and bringing it to new heights.
Under Playboy's leadership and rejecting Dwayne's old-fashioned views, the empire went from being exclusively about drugs to expanding into other realms of business, even legitimate. Still having the most success in drug sales, he became friends with Elizabeta Torres and monitored all drug deals in the city. After 2004, he stopped visiting Dwayne in prison, and being at a selfish point in his life, probably bought his yellow Patriot within a year or two of that date (assuming, like the real-life Hummer H2, it began production in 2003. It is unique to Playboy and can only be found with him).
Eventually he was introduced to Niko Bellic through a heroin deal and the two began a business relationship. Playboy X also makes a brief appearance in The Lost and Damned where Playboy refuses to meet Johnny Klebitz during the party.
Expanding into other businesses, Playboy even dreamed of leaving crime behind entirely to become a legitimate real estate developer and "see my name in big, gold letters!". He also explains his resolve to give money to poor young blacks and schools after he's wealthy to atone for selling drugs to children (although his penthouse and luxury car insinuate that he's already quite wealthy). He sought to win over Yusuf Amir, a billionaire developer from Dubai. Amir was under intense pressure to cooperate with the Mafia, who had shut down his construction site under the guise of a union strike in order to extort funds from him. X believed he could maneuver himself into Amir's favor by employing Niko Bellic to dispatch the mob gunmen besieging the site. Niko cleared out the site in the Playboy X mission "Deconstruction for Beginners", but Amir was unresponsive. Instead of rewarding X with shares in lucrative construction contracts, he permanently closed down the construction site in memory of those who had died. It is revealed in The Ballad of Gay Tony mission "For the Man Who Has Everything" that Amir continued construction on the soon-to-be Amir Towers.
Eventually Dwayne Forge is released from prison and tensions rise between him and X almost immediately. Playboy ignores Forge and attempts to distance himself from his former mentor, leaving Forge feeling bitter, heartbroken and betrayed. Playboy is still the Boss of the North Holland Hustlers, as eventually Forge retakes his former base of operations, the Triangle Strip Club, from associates of Playboy's, the Trunchez Brothers. Playboy is furious and it is clear that the bad blood between the former partners is going to come to a head.
Playboy X has a private conversation with Niko, claiming that Forge is talking behind his back and attempting to usurp leadership from him, even though he claims he offered half of the business to Forge. Though apparently very saddened by having to kill his mentor, he offers Niko $25,000 to kill Dwayne. Subsequently, Niko is also hired by Dwayne to kill PBX after word hits the street that there is a contract out on him.
If Niko chooses to kill Dwayne, Playboy has a change of heart, upset that his "father figure" was killed. Probably in denial, he blames Niko's cold-heartedness for the betrayal and although he pays Niko the $25,000 as agreed and wishes him the best, he severs all ties from Bellic and cannot be friends with him knowing he killed Dwayne. Later, his answering machine even claims that "you don't know what you got until it's gone."
If Niko chooses to kill Playboy, he shoots his way through Playboy's penthouse and corners him in an alleyway, easily executing him and returning control of the gang to Forge. Many players choose this path, as it coincides with Niko's moral code, is more challenging than killing Dwayne and brings much more rewards; Dwayne awards you Playboy's penthouse (which he reveals he had the deed to all along), and you gain Playboy's unique yellow Patriot and Dwayne becomes Niko's friend,