Alexis Ohanian Shares Photos of Special Vacation Moments with Serena Williams and Daughter Olympia

Alexis Ohanian and his daughter Olympia Ohanian are enjoying a little father-daughter time.

The Reddit co-founder, 38, shared a few moments from their vacation on his Twitter Monday.

He captioned a photo of him and the 4-year-old sporting their swim and snorkel gear.

"The last day of vacation hits different - let's get baaaaaaaack at it," the proud dad captioned the photo of his daddy and daughter activity.

Wife Serena Williams also enjoyed some time in the water zooming around on a waterscooter.

Alexis tweeted a video of the tennis star with the caption, "Mermaid?"

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The couple celebrated their fourth wedding anniversary on Nov. 16. Alexis posted a photo of him and Williams, 40, on their wedding day, along with a sweet message.

"4 years ago you made me the happiest man in the world and our little family keeps me feeling more grateful every day. Nov 16 will always be a very special day for our family," he wrote, adding "happy anniversary @serenawilliams — thank you for bringing this joy named Olympia into our life even though you always fall asleep in the middle of our movie nights."

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Williams also marked the day with a series of snapshots and a "stroll down memory lane."

"4 years later on this special day. I have so many fun memories. Stroll down memory lane with me. @alexisohanian here's to making each day together special. Happy anniversary," she captioned the photos.

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The duo welcomed Olympia on Sept. 1, 2017. While Olympia clearly has some serious water skills, she is also fast becoming a skilled pianist and, with her mom's help, and a tennis player.

In April, Williams told PEOPLE that she enrolled her daughter in tennis lessons to keep her occupied while in a socially-distanced environment.

"Honestly, we started because it's a socially safe sport, and when COVID happened, it was like, we're just in the house with a 3-year-old, what do we do?" Williams said at the time. "There was only one answer, to my dismay."

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Williams did go into "tennis mom" mode before Olympia's first lesson in October 2020, as she previously posted on Instagram, when she joked that the instructor had "no idea that it's my daughter, so we'll see how that goes."

"I'm not a pushy mom, but I know how I like techniques, I want to make sure she's good at teaching Olympia some techniques," Williams added.