Bruce Willis’ sex life has never been hotter since he met porn starlet Alisha Klass-and now we know why. GLOBE can reveal the shocking secret behind the sizzling sex that Demi Moore’s ex-hubby is going bananas for! Klass is a devoted user of the Kegelmaster?, a specially designed device that has gained an instant female following. The exerciser strengthens and tightens the vaginal walls, making for some unique erotic escapades.

“I can’t describe the intensity,” gushes the 29-year-old XXX-rated movie siren. “Many women ask me questions about improving their sex lives. My number one suggestion is always ?Get the Kegelmaster?!? Anything that can help women experience sex like this is a great product.”

And if anyone needs another testimonial, all they need to do is ask Willis about what the miracle gadget has done in the bedroom for HIM.

“Bruce is crazy about Alisha’s sexy moves and says she’s one of the most exciting women he’s ever known,” confides a source.

“He’s told his friends that making love to Alisha is sheer ecstasy.”

Willis should be a fan of the exercising device, too, because his curvy brunette galpal swears it makes men seem sexually bigger. “It makes every guy feel twice as manly,” Klass explains, “so he becomes a woman’s greatest lover.” Good results!