And it looks like it's true!
A source has confirmed to People that the pair have been seeing one another "on and off since their time working together on the movie last year," adding that "they are not officially dating." The publication also reports that Zac and Alexandra were recently spotted together at a pet store in LA.
That's a huge step in our books.
Earlier this month, Zac posted an Instagram tribute for Alexandra's birthday, making fans believe even more that they were a thing.
The photo shows Alexandra sitting on his lap, and the caption read, "Happy birthday to one of the the most real, down to 🌎, stunning, intelligent, creative, loving, and most rare Pokémon ever created."
Back in May 2017 Alexandra actually dismissed the dating rumours, while at the Billboard Music Awards.
"We work together closely; he's my love interest in the film," she said at the time. "I understand why people would go crazy over something like that, but Zac and I are very good friends."
But hey, a lot could have changed since then!