Brian Austin Green Thanks Girlfriend Sharna Burgess for Snapping Rare Photo of Him with All 4 Kids

Brian Austin green/ instagram; Matt Winkelmeyer/Getty

Brian Austin Green is soaking up time with his kids this Father's Day.

On Sunday, the actor, 47, celebrated the special occasion with a pool day with his four kids, sons Journey, 4, Bodhi, 7, and Noah, 8, whom he shares with ex Megan Fox, and Kassius, 19, whom he shares with ex Vanessa Marcil.

The Beverly Hills, 90210 alum shared a sweet photo to Instagram of him hanging with his kids in the water, writing, "Happy Father's Day everyone !!!"

Green gave his girlfriend Sharna Burgess a special shout-out in the caption, thanking her for taking the family photo.

"Thank you baby for taking such an amazing pic for me :))," Green said.

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The Dancing with the Stars pro also praised Green on the holiday, commenting on the picture, "Happy Father's day baby. You're amazing xx"

Last week, Burgess and Green opened up to PEOPLE about their relationship.

"We met at a coffee shop, then had a few dates and then we were locked in a house together," Burgess, 35, said. "I was grateful for that because it allowed us to really take our time and it was really awesome."

Meeting Burgess "was something I'd never experienced before in my life," said Green, who officially split from Fox last year. "On our first date, we just completely lost track of time and the same thing happened the next time. It became something noticeably different from anything I'd ever experienced before."

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Continued Green: "I wasn't sure what that meant until the first time we kissed and then it was the attraction and a whole bunch more. It was really cool. And we really have the same moral compass."

The father of four and the dancer have been dating since late last year. "They are casually dating and having a good time. They are currently vacationing together," a source told PEOPLE at the time when the couple went to Hawaii.

Burgess has since raved about Green and Fox as co-parents. "He's a wonderful dad, and he and his wife - uh, ex-wife - have raised three beautiful children," she said on The Morning Show in February. "And they are so wonderful and sweet and kind and considerate, and they've done such an amazing job."