Channing Tatum, Zoë Kravitz's Romance Hits One-Year Mark with Steamy Vacation: 'It's Serious' (Source)

Channing Tatum and Zoë Kravitz have hit the one-year mark in their relationship and are "very happy" together, a source says.

"They are very happy. Their careers are a big focus and they share this passion," the source tells PEOPLE in this week's issue. "When they are off, they are very low-key. They enjoy quiet date nights with friends but most often just hang out at home."

Adds the source, "Channing is serious about Zoë. It's not a casual relationship. They have been exclusive for a long time."

The couple — who connected early last year when Kravitz, 33, tapped Tatum, 42, to star in her directorial debut Pussy Island — were recently spotted together on vacation in Positano, Italy, along with Tatum's daughter Everly, 9. And though the stars were photographed kissing on a yacht over the weekend, Tatum and Kravitz try to keep their relationship out of the public eye.

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"They were in Europe and not expecting the world to see them, although that is kind of naive," says a separate insider. "The romantic relationship is quite intense and positive for both of them. It is serious, but I don't see them going public in a big way unless something forces it."

Tatum still prioritizes time with his daughter, whom he shares with ex Jenna Dewan. Everly has also spent time with Kravitz.

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"Channing has a blast with Everly and enjoys life as a dad," adds the insider. "Zoë sees the depth of character and a hidden maturity, a person who thinks quite a bit. She is impressed with all of that. They have enormous respect for each other above and beyond the romantic attraction."

Last August, PEOPLE confirmed the the stars were dating after they were seen going on bike rides, museum visits and coffee dates around the same time Kravitz finalized her divorce from actor Karl Glusman, 34. Tatum and Dewan announced their divorce in 2018 after nearly nine years of marriage.

For more on Channing Tatum and Zoë Kravitz, pick up the latest issue of PEOPLE on newsstands Friday