For her part, Wei felt strongly this was no time for timidity. "I had to be this woman. I had to do what she would do. Telling this story without the love scenes would have been impossible," says the soft-spoken actress.
Based on a short story by Eileen Chang, the film centers on young Chinese resistance fighters targeting the occupying Japanese forces in World War II Shanghai. Idealist Wong Chia Chi (Wei) volunteers to become the mistress of Mr. Yee (Tony Leung), a traitor who runs the secret service. Convinced that if she beds him, the fighters can assassinate him, Wong Chia Chi gets to Mr. Yee by infiltrating his wife's mah-jongg circle. Soon Mr. Yee spots the fetching freedom fighter and makes her his lover, drawing her into sex sessions that are as savage as his insatiable lust dictates.
Though some critics have described the erotic espionage thriller as rough porn and the Motion Picture Association of America has slapped it with an NC-17 rating, the actress feels the audience's attention should be turned elsewhere.
"Everyone is focusing on the love scenes, but once they watch the film they'll understand how important they were in presenting the emotional struggle between these characters," she says.
The rehearsals for these steamy tête-à-têtes were "very private," says Wei, with just herself, Lee and Leung on set. "Ang made me feel very comfortable, so I didn't worry," she says.
She put her trust in Lee from the outset, first meeting him during the audition process when Lee fixed a cup of tea for Wei, who was suffering a fever. "It surprised me. I thought, 'Here is this big director trying to make me feel better,'" Wei smiles. "At that moment I knew I'd be happy to work for him."