The 53-year-old actor insists that his alter ego's depression with the state of his relationship and desperation to stay faithful to Sunita is "honourable".
"Dev would be devastated if he lost Sunita. He loves her and their children, so this makes him take stock," he told Inside Soap.
Harkishin also outlined his belief that Dev would "even be prepared to sweep an affair under the carpet if it meant his family was secure".
"I think his behaviour is honourable," he added of the shopkeeper.
Next Wednesday (June 6), Dev confronts Sunita when he finds her packed suitcase, before accusing her of cheating on him in the next evening's instalment.
Wild Sunita (Shobna Gulati) has been having an affair with Rovers Return landlady Stella Price's partner and gambling addict Karl Munro (John Michie).
> Coronation Street's Shobna Gulati: 'Sunita's in love with Karl'
> Coronation Street Shobna Gulati "cried" before love scenes