It’s official: Amber Heard has a new man.

Heard and billionaire tech mogul Elon Musk stepped out together for the first time in public while in Australia over the weekend.

The actress, 31, and the Tesla founder, 45, spent Sunday at the Gold Coast’s Currumbin Wildlife Sanctuary, where they walked arm-in-arm through the reserve and held hands as they took part in a zipline ropes course.

Later that night, Heard shared a photo of herself resting her arm against Musk, a kiss mark clearly visible on his cheek. Musk also shared a similar photo on his own account.

Cheeky

A post shared by Amber Heard (@amberheard) on Apr 23, 2017 at 5:11pm PDT

So when did these two get together? Dating rumors started swirling last year when they were spotted out together on multiple occasions amid their respective divorces from Talulah Riley and Johnny Depp.

The actress and Musk, whose fortune has been estimated at $15 billion, were first seen together in Miami, where they were both staying at the Delano South Beach in July 2016. Two weeks later, they were again spotted together at a London nightclub.

Amid speculation about a romance, a source told PEOPLE, “Amber and Elon are friends and have been for a few years.”

Later that summer, the source confirmed a Hollywood Reporter report that Musk sent emails to Machete Kills director Robert Rodriguez in 2013 asking to meet Heard, but added that the tech mogul simply likes to get to know “interesting people from all different industries.”

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“They have been friends for four years, and they remain just friends now,” the source explained to PEOPLE.

In March, both attended a VIP movie screening of Al Gore’s upcoming documentary, An Inconvenient Sequel: Truth to Power, in California.