As revealed over the weekend, Mercedes will soon share a kiss with Riley (Rob Norbury) in The Dog - just days after the tragic death of her husband Malachy.
Speaking to Soaplife about her character's surprise decision, Metcalfe explained: "Mercedes is just being Mercedes. She figures there's nothing she can do, there's no point moping. She has to just get on with her life."
She continued: "He's giving her attention when she needs it most."
Pictured: Mercedes and Riley lean in for a kiss at The Dog.
In a further twist, sexual tension will also develop between Mercedes and Carl Costello (Paul Opacic) after he warns her to stay away from his son.
Metcalfe added: "Mercedes asks Carl what he'll do if she doesn't stay away from Riley - sleep with her himself? She really says it to wind him up but it turns out she's hit a nerve. It's obvious he's tempted."
Reports suggest that subsequent scenes involving the trio will see a love triangle storyline develop on the soap.