"She spends a lot of time at his house and is very comfortable there," a source tells PEOPLE of Amber Heard and Elon Musk.
DO NOT REUSE! DO NOT REUSE! Amber Heard goes public for the first time with billionaire boyfriend and Tesla boss, Elon Musk.
Credit: MEGA

Not unlike his new U.S. spy rocket, Elon Musk‘s relationship with Amber Heard is really taking off.

The billionaire tech mogul, 45, and Aquaman actress, 31, have been spending a lot of time together, and a source tells PEOPLE, “Elon and Amber are already very serious about each other.”

The source adds, “She spends a lot of time at his house and is very comfortable there. Amber’s also gotten to know his kids and spends time with them as well.”

For fun, the source says Musk “takes her on romantic dinner dates and they also love hanging out in Malibu.” Overall, the SpaceX, Tesla and PayPal founder has seemed “noticeably happier since he started dating Amber.”

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Musk was first spotted spending time with Heard, 31, after her divorce from Johnny Depp, but the tech mogul first took an interest in her when he made a cameo in Robert Rodriguez’s 2013 film Machete Kills, in which Heard had a role. The two were recently spotted out to dinner together on April 30 at Century City’s RockSugar in L.A. An onlooker tells PEOPLE they seemed to be enjoying each other and shared a couple appetizers. Both were dressed casually, Heard was wearing a stylish printed black blouse with a sun hat and Musk was wearing a black t-shirt and baseball cap.

“When the time was right and they were both single last year, he started pursuing her romantically,” a source previously explained of the twice-divorced Musk, who was previously married to Talulah Riley and Justine Musk. “She was playing hard to get for a while, which made him even more interested.”

The billionaire also has plenty to celebrate outside his love life. On Monday morning, SpaceX successfully launched a classified U.S. spy agency mission into orbit before bringing the rocket home for a landing.

After nearly scrapping Monday’s launch due to strong high-altitude winds, Musk confirmed the mission was a success. “Launch and landing of the NRO spy satellite was good,” he wrote. “Tough call, as high altitude wind shear was at 98.6% of the theoretical load limit.”

  • Reporting by MELODY CHIU