The actor, who was cast in the role of Paul Robinson's son Andrew last year, was required to lock lips with co-star Margot Robbie (Donna Freedman) during his first day on set.
Reflecting on the experience, Smith commented: "It's bit weirder in rehearsals because you come face-to-face and don't kiss. You're just kind of breathing on each other. But when you kiss it's pretty fun actually!"
Speaking to the show's official website, he added: "When I told my mates I'd be kissing Margot Robbie they were pretty stoked. I didn't know who Margot was. I hadn't watched the show before. But when I saw her I thought, 'This isn't going to be difficult'.
"Because she's such a good actress and she's really professional she made it really easy. She talked me through it and said 'don't worry about it'."
Smith's first scenes will air on UK screens next week.