author Cash Carraway, is set in England and follows struggling and impoverished single mother Costello Jones (Cooper), her daughter Iris (Fleur Tashjian) and Costello’s best friend Selby (Jack Farthing, “Poldark”) — a wealthy gay man who is Costello’s pseudo “soul mate” and Iris’ father-figure. “It’s an unconventional love story, really,” Cooper, 36, told The Post. “[Costello and Selby] are from opposite ends of the spectrum. He’s very affluent, she’s poor, and they’ve both been neglected in different ways and haven’t got the skills to have a normal healthy relationship, so it gets toxic.