A single, passionate kiss upends the lives of a pastor and a young woman in the Hong Kong movie Heaven In The Dark.

In separate telephone interviews from Hong Kong, actors Jacky Cheung and Karena Lam are nonchalant about the filming of the scene, even though the director is none other than Lam's husband, Steve Yuen.

Cheung, 54, says breezily: "There were no NGs (no-good takes) and we filmed it twice. I guess the director didn't want me to kiss her for too long either."

Lam, 37, points out: "Everyone is really professional, so the kiss didn't faze us."

It helps that they had previously worked together in the awardwinning July Rhapsody (2002), in which she had played a high-school girl seducing him, her character's teacher who was in a midlife crisis.

Lam, then a rookie star, swept the Best Supporting Actress and Best Newcomer prizes at the Golden Horse and Hong Kong Film Awards ceremonies. Cheung was nominated for Best Actor at the latter event.

For the new film, neither of them won although both were nominated for acting prizes at the Hong Kong Film Awards.

Cheung says of his professional reunion with Lam: "I'm familiar with her and we know each other well, I know the director too, so there won't be any misunderstandings. The biggest difference this time is that she's now a very professional actor and doesn't need that much time for preparation. Back then, she was a newcomer. Although everyone hailed her as a genius actor, she still had her insecurities. Those are completely gone."

Although a theme in both Rhapsody and Heaven - which opens in cinemas tomorrow - is temptation, Cheung says that it has not been a problem for him, despite being one of the four heavenly kings of Hong Kong entertainment.

"Maybe it's something to do with my looks. Also, I got married pretty early and had kids, so things are quite clear-cut in my case," muses Cheung, who is married to former actress May Lo. They have two daughters aged 15 and 10.

Lam takes a more philosophical approach in her response, saying: "Temptation is everywhere, be it in the form of money or power, so it depends on how you face it. I would rather not test myself because we are all weak as human beings."

Last year marked her return to the movies after she took a hiatus of a few years to raise her two daughters. Her turn in the drama about loss, Zinnia Flower (2015), won her Best Actress at the Golden Horse Awards.

She says: "Promoting a film and award ceremonies feel very far away from me. What I enjoy most is acting on set."

The experienced actress also gives her husband the thumbs-up on his directorial debut. "He's an experienced commercials director, but that's still a different realm. That he's managed to tell the story he wants to tell is quite something."

•Heaven In The Dark opens tomorrow.