Kim Cattrall's self-help book Satisfaction: The Art of the Female Orgasm should come with the following disclaimer: May cause performance anxiety in the actress-author's Sex and the City bedmates. "I found out about [the book] halfway through shooting," says Mutant X adonis Victor Webster, who plays a sleazy stockbroker seduced by Cattrall's sexually voracious alter ego Samantha on Sunday's season premiere (9 pm/ET on HBO). "I was like, 'If this was real-life, I would be very intimidated.'"

After his Sex stint reached its climax, Webster nonetheless had the cajones to not only purchase Cattrall's graphic guide to pleasure, but read it cover to cover! His reaction? "She's got a pretty good understanding of the orgasm," he laughs. "She was very explicit and open about sharing everything, and that's really the way to learn."

So, what was it like filming those red-hot Sex sequences, which, in addition to handcuffs, featured enough screaming and yelling to drown out the blowhards on the floor of the New York stock exchange? "It was kind of an awkward thing," he admits, "because you have no clothes on and you've got 70 people around you and you're handcuffed to a bed. And then you have this little piece of fabric covering your goods. You feel really vulnerable and exposed, but you just have to overcome that and make the scene work. It's a challenge."

Luckily, Cattrall — an old pro at reel sex — put him at ease. "You wouldn't expect somebody at that level to be so down to earth as well as so talented," marvels the newly single actor, who next week begins work on the third and final season of Mutant X. "She has this inner — as well as outer — sex appeal. It's just amazing." Well, someone's certainly mastered the art of the female compliment.