Congratulations are in order for Michael Phelps, who just welcomed his second baby with wife Nicole Johnson on Feb. 12! "Magical moments yesterday… Nicole and I would like to introduce Beckett Richard Phelps to the world!" he wrote on Instagram, alongside a sweet photo of his son Boomer and Nicole in the hospital. "We had a healthy baby boy and a healthy mama. I truly do feel like the happiest man in the world. Being able to build our family to now 4 (6 with doggies) is so incredible! #familyof4now."

Nicole posted her own photo and captioned it, "Our family grew by 1 yesterday ? meet Beckett Richard Phelps. I’m surrounded by boys and I couldn’t be happier ???." So sweet! The duo announced they were expecting their second child in August 2017, when the Olympic athlete shared the exciting baby news on his social media — along with a photo of his son Boomer.

"Number 2 on the way!!!! So excited!! Wonder if it's a boy or a girl??," he captioned the sweet pic of Nicole with their 15-month-old little boy — who is proudly holding up a pregnancy test. Nicole also shared the news on her personal page, writing, "Lil mans going to be a Big Brother!!!" As expected, fans quickly flooded Michael's feed with well-wishes.

"Congrats to you, your wife and Boomer's becoming big brother. I hope it's a girl," one follower wrote before another jokingly added, "It's probably going to be a fish."

When it comes to fatherhood, Michael took like a fish to water (no pun intended) and revealed he's not pushing his son to follow in his footsteps. "If he wants to! I will not push it," he said on The Today Show. "My mom never really pushed me to do anything. It was kind of, we learned on our own, and I fell in love with a sport."

He also gushed about his wife after the couple secretly tied the knot late last year. "Watching her as a parent, watching her as a mom, she's the best. She's always reading things and just trying to make sure that his life is the best that we can make it."

As for coming out of retirement, it looks like Michael is very happy just being a hands-on dad. At the 2016 Olympic Games, Michael won five more gold medals, bringing his total medal count to 28 medals. Congrats to the growing family!