Events unfold when Tina returns from London to collect her things and nosy Norris overhears her telling Carla the reason she left so abruptly was because of her kiss with Rob.
Armed with the gossip, it's not long before Norris relays what he knows to Tracy.
"She just can't believe it," said actress Kate Ford, who plays Tracy.
"Every relationship that she's had so far hasn't gone well for her so she doesn't want to even consider that this man who she thinks is better than the rest could have betrayed her."
And when Tracy confronts Rob, he denies the kiss.
"Rob tells her that no one else does it for him and that she's the one," explains Kate.
"I really believe he was being honest with her as well. He snogged Tina because she's pretty, but he does really care for Tracy."
But it's not long before Tracy takes matters into her own hands to get to the truth.
"She goes to the Rovers and tricks Tina into confessing. She loses it at this point and throws drinks in both Rob and Tina's faces. She's completely heartbroken."
Furious Tracy throws Rob out, but even mum Deirdre thinks that she is making a mistake by letting him go.
"Deirdre asks her if she's being too hasty. He is a good guy, he hasn't slept with Tina and he's obviously into her."
Enraged by Rob's betrayal, Tracy tries to sell his belongings at Barlow's Buys in an attempt at getting back at him for hurting her.
But when Rob finds out Tracy has sold his stuff, he tells her that he won't put up with her games.
"She has overreacted, but you don't cross Tracy. He warns her he won't spend his life apologising for a stupid mistake, and this does make Tracy think.
"Tracy can either forgive and forget or not. If she chooses not to she could lose Rob and she really doesn't want that to happen."
Coronation Street airs on UTV Monday, Wednesday and Friday from 7.30pm.