The swimmer, 32, celebrated the upcoming arrival of the couple’s second child with a baby shower on Sunday. He shared a photo holding 21-month-old son Boomer Robert and standing next to Nicole, whose growing belly was on display in a fitted green dress and sleeveless beige cover-up.
“Thanks to those who came to celebrate today!!” Phelps captioned the family photo, adding the hashtag #babyshark, which guests used to share their snaps. (Perhaps it’s a reference to the 28-time Olympic medalist racing a shark as part of Discovery Channel Shark Week?)
Nicole, also 32, posted a sweet shot of her husband with his hand on her bump. “Such an amazing day celebrating our #babyshark!!” she wrote. “More photos to come … we are so thankful for everyone who was able to be with us and everyone who was with us in spirit.”
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RELATED VIDEO: Michael Phelps and Wife Nicole Expecting Second Child
In August, the couple announced in matching social media posts that they are expecting again.
Phelps and the former Miss California USA welcomed Boomer in May 2016. They wed later that year – twice! First, the pair tied the knot in June, and then again in late October during a larger event in Cabo San Lucas, Mexico.
Phelps previously revealed to PEOPLE that his wife was looking forward to growing their family, sharing, “Nicole has recently brought up that she would like a girl!”
“We definitely want more kids, it just depends on when,” he added, noting “I’m sure I’m getting pressure” and teasing, “ trying to get moving on some things!”
In another interview, the athlete further told PEOPLE of more children, “We are so fortunate to have a healthy and happy baby and hopefully more coming soon, but we don’t know when.”
“We’re going through life every day happy and blessed with what we have. But I hope to have more kids in the future,” Phelps explained.