Ava Moore was originally Avery Tanner, a gay man who worked as a professional escort to wealthy older women. Avery was in love with Dr. Barrett Moore, and used his charisma to convince his wealthy female dates to finance Moore's medical research.
However, to Avery's growing disappointment, Barrett Moore was a confirmed heterosexual and refused to advance his friendship with Avery to the level of a romantic relationship. Avery fell into a deep depression and, determined to have Moore's love at any cost, asked the doctor to perform sex reassignment surgery on him. Intrigued, Moore agreed and personally undertook the mission of transforming Avery into Ava. Moore's skill as a surgeon allowed him to turn Avery into what Christian Troy would later describe as "The Hope Diamond of transsexuals; completely flawless in every way." Ava was happy with her new form and the two married. But problems quickly popped up, as Moore could never truly accept Ava as being a woman and instead treated her like his prized creation. Ava sank further and further into depression. Moore arranged for one of his female employees to become pregnant with his child so Ava could become a mother and hopefully pull the three together as a family.
Ava grew increasingly distant from her husband and ultimately took their child and left in the middle of the night — right before the final surgery was to be performed to make her vagina deep enough to pass as biologically natural. She then began taking young lovers, since Ava believed that younger, sexually inexperienced boys would not be able to tell that her genitals were different from those of most women.
Ava Moore was introduced at the beginning of season two as a life coach who is hired by plastic surgeon Sean McNamara to "motivate" his emotionally distant wife Julia into becoming a better wife to him. Sean's attraction to Ava blinds him to who she truly is: a sexual predator who targets and exploits the emotionally weak in order to manipulate them for her own amusement. Upon meeting Julia, she finds that Julia's distance comes from her attraction to Sean's best friend and business partner Christian Troy, as well as the recent revelation that Christian is the father of her first-born son, Matt. From there, Ava moves onto Matt and seduces the teenager into a sexual relationship. The relationship is met with scorn from Ava's own teenage son, Adrian. It is ultimately revealed that Ava's sexual predation extends to her own son, who is jealous of the attention his mother gives to Matt.
When Matt's relationship with Ava is exposed, Ava uses the truth about Matt's paternity to try and silence Julia, but the truth ultimately comes out. Matt moves in with Ava and continues to act out on his anger at his parents. His delinquency is also influenced by his friendship with Adrian, who was molded long ago into a sociopath by his mother's abuse. When Matt tries to expose Ava, she reveals that she is not Adrian's biological mother; she told Matt that she and her "son" had a prior conversation about the abuse ending in sex (with Ava clearly guilty about the incest and Adrian begging for his "mother" to "make love" to him). The shock of these revelations causes Adrian to run away, and Ava becomes more and more depressed and withdrawn from Matt.
At the end of the second season, Ava has a confrontation with Christian Troy over her relationship with Matt. During the confrontation, Ava begins taunting Christian sexually, to the extent that Christian snaps and begins to have forceful sex with Ava. During the intercourse, the sexually experienced Christian makes a shocking discovery; Ava has an extremely shallow vaginal canal and has to be a transsexual. Researching Ava's history to confirm the revelation, Christian and Sean discover her past by speaking to Barrett Moore.
Confronted with the truth, Ava expects her enemies to expose the truth about her and destroy her life. The three are sympathetic towards her, however, and together strike a deal in which they would help arrange for Moore to complete the final surgery on Ava's genitals in exchange for Ava breaking off her relationship with Matt, as they fear his reaction to her true identity.
The surgery is successful, and Ava breaks up with Matt. At first Ava tries to be cruel in order to create a clean break, but Matt refuses to back down. Ava then explains to Matt that she couldn't stay with him because their relationship had awakened personal demons that she has to face on her own.
Hours later, as Ava prepares to leave the country, Adrian confronts his mother with a knife. After an intense exchange, Adrian turns the knife on himself and commits suicide. The last scene of Adrian is on Ava's floor, where it left to be assumed by the viewer that Ava leaves her adopted son's body to rot. She boards a plane to Paris very shortly after.
As of the end of the third season, Ava Moore remains in France and has yet to return to the United States. The character does, however, make a brief appearance in season three, through use of deleted scenes of Ava and Matt making love (which were edited to appear as a dream sequence) and a scene where Matt, having learned the truth, imagines Ava appearing before him; in the dream, she curses him for hating her, and demands that he come to terms with the fact that he still loves her even if she was born a man.fr:Ava Moore