The EastEnders actress called off her wedding to Morse last August when she discovered he had been sending lewd emails to an ex-partner.
Kat Slater star Wallace has since been pictured kissing musician Tim Arnold, who confirmed the relationship earlier this month and claimed the pair are "in love".
Referring to his public apology on This Morning, Morse told The Sun: "I did all I could to get her back but she didn't want to know."
While accepting Wallace's new romance, Morse expressed his concern over Arnold's previous problems with drugs.
Morse added: "It's lovely that she has found love. I worry that he's a former crack addict, but I hope it works out for her."
Wallace and Arnold met at the British Soap Awards in April, as the former Britpop star is son to EastEnders cast member Polly Perkins (Rose Cotton) and godson to legend June Brown (Dot Branning).