Michael Douglas and Catherine Zeta-Jones have a combined age of 135, but they're still acting like a pair of newlyweds and crediting their insatiable sex drives as the key ingredient in their long-lasting love story.

Jones' $21.5m Central Park home with her husband Michael Douglas has grand gilded gold features - see rare photo

Celebrating their shared birthday on Sept. 25, Catherine Zeta-Jones and Michael Douglas were joined by a very special guest: Bono, who appeared in an Instagram video the 'Wednesday' actress shared depicting their intimate festivities.

On Thursday, Zeta-Jones posted a video that featured her and U2 vocalist Bono serenading Douglas with the “Happy Birthday” song as they held a dessert with a lit candle. The celebrity couple wed in 2000 and share two children together. Douglas also shares a son with his ex-wife, Diandra Luker.

The Chicago actress cut a casual figure in black tracksuit bottoms, a suede jacket and black trainers, sweeping her glossy raven hair into a messy low bun. As Catherine planted a kiss on her husband's cheek, Michael also pouted, wrapping his arm around his wife's waist.

As Michael Douglas celebrates his 80th birthday, here is a look at his long-lasting relationship with Catherine Zeta-Jones.

Catherine Zeta Jones and Michael Douglas have been married since 2000, after the Hollywood icon was smitten watching the Welsh actress in the movie The Mask of Zorro

Michael Douglas and Catherine Zeta-Jones have long been synonymous with Hollywood stardom, and now their daughter, Carys Zeta Douglas, is poised to continue their legacy. At just 21, Carys has already begun to make her mark in the entertainment industry while balancing her academic pursuits.