Terry Milkovich is the father of five sons and two daughters. He is known to have escaped arrest numerous times, which caused Frank to turn to him when he needed a water-tight alibi to stop the police questioning him about the death of Eddie Jackson. He is arguably one of the two main antagonists of season 3. The Milkovich is of Ukrainian descent. Because of Svetlana's use of the Russian Orthodox church for Yeveny's baptism, it is possible his the Milkovich's aligns with the Russian Orthodox church which could explain his Terry homophobic beliefs and his own history of internalized homophobia.
He very nearly caught Ian and Mickey the first time they slept together, but despite finding them naked together, simply told them to put some clothes on and thought nothing of it, probably assuming they were on drugs. It is later discovered, due to his constant drinking and blackouts he had unknowingly impregnated his daughter Mandy. Around this time Terry had hunted Ian down because he thought he was the father, until Ian and Lip tried to plant an illegal gun in his possession, only the plan back-fired when Terry came home. Terry made a reach for the gun as Ian and Lip began to run. Lip managed to jump out of a window. Ian however, got cornered by Terry in the kitchen only to have Mandy interfere by holding a shot gun to him. As it turned out the father was in fact Terry. The revelation of his impregnating his own daughter disgusted both Ian and Lip.
Additionally, Terry owns more guns and leaves the house unlocked on purpose since, according to Ian, anyone would be crazy to break into the Milkovich's home. He's noted to dislike the older Gallagher boys.
It hasn't been revealed if he was married, or dating the mother of the Milkovich family, who is mentioned being dead during Season 2 in a conversation between Ian and Mandy.
In Season 3 Terry finds out about Mickey's sexual orientation and takes matters into his owns hands to "straighten" Mickey out. He walks in on Ian and Mickey having intercourse and attacks Ian, shouting "Mandy wasn't enough?". Mickey tries to interfere and manages to wrestle Terry away from Ian, but ends up receiving the brunt of Terry's beatings himself. As Ian tries to run, Terry points a gun at Ian and tells him to sit back on the couch. Mickey, barely conscious now, tries kicking Terry off, but Terry hits him with the base of his gun and puts Mickey out. He then calls a Russian girl over to have "corrective" sex with Mickey. When the girl arrives, Terry tells Mickey she is here to "fuck the faggot out" of him. Terry forces Mickey to have sex with her and makes Ian watch. Mickey is seen to be in pain and looks at Ian, but Ian can't return his gaze, emotionally in pain himself. After a short while, Mickey rolls on top of the girl and away from Ian, so that his back is to Ian and he wouldn't see him. He acts like he is suddenly enjoying the sex to get it over with as soon as possible, while Ian watches in dismay.
In Season 4, while the prostitutes are stuck at the Milkovich home for a time duration, Svetlana and the others yell at Mickey while Svetlana adds that he "also has small dick". Terry blames Mickey as well for trying to "liberate" the prostitutes and adds "You do have a small dick" and "This is my house". Terry says it is indeed his (Mickey's) fault because he actually believed the prostitutes deserved more (pay) and thought he could "liberate" them, and says from his (Terry's) experience, she (Svetlana) is not worth anything more.
In Iron City, Terry is seen being hauled from his house by several policemen while yelling profanities at them. He had apparently failed another urine test, thus violating his probation. He is sent back to prison.
In Emily Terry is released to go to the christening of Mickey’s son, and arrives later at the Alibi. Mickey and Ian fight about their relationship and, before Ian leaves, Mickey gather's everyone’s attention to announce that he is gay. Moments later, a furious Terry lunges for Mickey and instigates a bar brawl. Mickey and Terry are apprehended by the police while Terry continues to shout homophobic slurs, and continues his aggression as Mickey provokes him. Terry is taken away by the police for breaking probation just hours after his release, while Mickey is released by a gay cop.