Katie Holmes and Jamie Foxx, who were rumoured to be in a romantic relationship since meeting each other at a Hamptons gala in August 2013, confirmed their romance by stepping out in public for the first time with the two holding hands and frolicking on a beach in Malibu over Labour Day weekend.

So, how did Holmes and Foxx keep their romance a secret for more than four years?

According to HollywoodLife, the couple "worked hard at keeping" it that way, meeting mostly late at night at their "secret rendezvous", and the Django Unchained star leaving the actress before anyone noticed he was even there.

"Katie and Jamie worked hard at keeping their relationship quiet for several years," a source told the celebrity gossip news website. "They arranged regular, private, late-night, secret rendezvous with at her place weekly when they first started seeing each other. They enjoyed romantic, sleepovers together at her Calabasas mansion where Jamie would leave early in the morning before anyone noticed he was even there."

"It was their own secret romance for a long time which made things exciting, sexy and fun," the source said, and added that the couple are taking their relationship one step at a time.

"Katie is madly in love with Jamie, but she really has no desire to get married and to have more kids," the source said.

Holmes shares daughter Suri with former husband Tom Cruise, who is reportedly feeling "betrayed" by his former wife's secret relationship with Foxx. Cruise and Holmes split in 2012.

Cruise is said to be "shocked and upset" with Holmes dating Foxx, who he once considered a friend.

"Tom has known about Katie and Jamie's secret relationship since the beginning and it has always bothered him that they were hooking up. While Katie and Jamie did their best to keep things a secret from the world, Tom is too well-connected and found out about them shortly after their romance began," a source previously told the celebrity gossip website.

"Tom is shocked and upset that Katie is dating a co-star he once considered a close friend. He feels betrayed by both of them," the source added.