Last night, viewers saw Tina fall and hit her head during a furious showdown with Terry. However, as Tina receives emergency medical treatment this evening (May 10), Terry tries to cover his tracks by telling Tommy that loan shark Rick Neelan is to blame.
Tommy does not discover the truth until Friday night's Coronation Street double bill, when the storyline reaches its climax.
Fountain told itv.com: "Terry being Terry, the rogue that he is, you find out at the end of this week that he's never had any regard for Tommy - he's never had any feelings for him and he's never had any intent of staying around and being his dad.
"After Tommy realises that it's Terry who's hurt Tina and not Rick, he's furious to start off with. But then he's still got that hope that his dad will stay around and be a part of his life."
The actor said that he can understand why Tommy has been fooled by his villainous father.
He explained: "Tommy's in a bit of a predicament, really. Obviously Tina's the love of his life and is the first girl he's fallen for. Yet his dad is his dad - it's a blood relationship and it's the only member of true family he's got left."
Discussing Tommy's ongoing struggles, he added: "Tommy's in a position he's never been in before. There's loan sharks, debts, money and people getting beaten up. He's not quite sure what's going on, but we've just got to see how he deals with it."
Coronation Street continues tonight at 9pm on ITV1. Get the Inside Soap magazine on your iPhone or iPad