Terry Hay is the abusive step-father of Ste Hay. He was mentioned in 2006 when Ste arrived at school with bruises on his face. In October 2007, Terry tried to convince the Barnes family that Ste was a danger to their daughter, Amy, and her baby, Leah. When they arrived at Ste and Amy's flat, Terry began beating Ste, but Mike Barnes pulled him off and threw him out. A few months later, after Ste had a visit from his mother, Pauline Hay, Terry told them that things always got bad for him when Pauline started whining about Ste. He almost broke Ste's finger, and told them he'd call the cops on them unless they stayed clear of him and Pauline. In March 2008, Pauline showed up again and told Ste that she and Terry had split.
In 2014, Terry visited Ste to apologise for the abuse directed towards he and his mother, and told him that his ex army step father used to beat him too eventually Ste forgave him. Ste told him that he and John Paul McQueen were getting married, and invited him to attend the ceremony. Terry had to decline due to work conflicts, but gave them his blessing.
Terry returned once more in January 2019, having been contacted by Sinead Shelby, who was concerned that Ste was being manipulated by Jonny Baxter into believing him that he was his brother. Terry attempted to make Ste see sense, but he was unable to and Ste continued to believe Jonny. Then, needing somewhere to stay, Terry then asked Ste if he could spend the night at 2 Oakdale Drive. Ste was accepting of Terry and believed he could actually be a changed man, but this was not the case, as Terry stole £20 from Leela Lomax's purse whilst his back was turned.
The next day, Terry asked Ste for money so that he could get suited and booted for a job interview. However, when he later showed up at The Dog in the Pond inebriated, Ste realised his step-father hadn't changed one bit and wanted him gone. A bitter Terry intimidated Ste and insisted he'd only leave him alone if he helped him steal TVs from the Bean. Ste agreed to help Terry by removing the CCTV's memory card, but then proceeded to call the police as Terry began his illegal activity. An infuriated Terry evaded the police and gave Ste a beating when they next came face-to-face. Jonny then learned of Terry's abuse towards Ste and had Terry hospitalised by thugs. Ste made it clear he wanted nothing more to do with his step-father at his bedside and swiftly left, while Jonny smirked, knowing that whilst Terry was correct about him not being of any relation to Ste, Ste would never believe his step-father over him.