Tilly Keeper says Louise Mitchell "is obviously devastated" when it is revealed her fiance Keanu Taylor had an affair.
Tilly Keeper
The 'EastEnders' actress has revealed her character's world will be torn apart when she discovers her partner - played by Danny Walter - is the father of her step-mum Sharon Mitchell's (Letitia Dean) unborn baby.
However, Tilly confessed that her character's reaction may surprise some fans when the secret is exposed over the Christmas period.
She told Digital Spy: "It's a reaction I don't think anyone will expect! Of course, she's a young girl and her fiancé has cheated on her, so she's obviously devastated."
Her dad Phil (Steve McFadden) has already discovered Sharon was unfaithful, and he begins questioning his daughter about his wife's behaviour.
Louise instantly becomes suspicious but tries to brush it off as she wants to celebrate the festivities with her baby girl.
Tilly added: "It definitely sparks a suspicion! Louise is so caught up in her own life and drama so when that reality is brought to her again, it does spark something but she doesn't want to play on it too much because she wants to have the best Christmas with her baby girl.
"But there is an underlying tension of her remembering her own suspicions from the last year."
But as the truth slowly slips out, Louise is determined to get to the bottom of Keanu's scheming.
Tilly said: "She's got that kind of scheming side to her and she knows how to manipulate people. She's definitely trying to manipulate the truth out of both parties so she's playing the field between Sharon and Keanu by separately quizzing them about last year.
"But with every answer they're giving her, it's feeding the fact that she's really trying to deny the truth even to herself."
Tagged in Letitia Dean Steve McFadden