Fatherhood is having a transforming effect on Dancing With the Stars bad boy Maksim Chmerkovskiy. The new dad, who welcomed son Shai with fiancée Peta Murgatroyd on January 4, marveled at how his life has changed in a sweet Instagram post.

"It's been one week plus one day of my fatherhood and I'm the happiest person that’s ever lived," the dance pro, 36, captioned a black-and-white pic that showed him cradling his son (who was not visible) on Thursday, January 12. "I'm also feeling very protective and now understand what every parent in history have been going through for as long as humans have been giving birth."

"I don't let too many people come see my son and I don't want to put any of him on social media just yet," he continued, adding that he and Murgatroyd, 30, "just want to enjoy our little family, together with our loved ones, and take in all the precious moments which we'll never get back. So be sensitive please. Or not. Either way, hope everyone's year is off to an incredible start. Ours sure started with a bang P.S. Farts, poops and throw-ups are the best!"

The new mom also shared an update on their first child, posting a pic of the baby's nursery on Instagram on Thursday and writing, "I would like to take this opportunity to say thank you for all the well wishes for our little Shai. I've read all the beautiful blessings and he is without a doubt a lucky boy."

"He is a healthy boy with an incredible appetite for food and love," the DWTS pro continued. "We can't wait to share him with you, but for the first most crucial weeks of his life we're just keeping him for ourselves and soaking up these moments. Thank you for your patience and all of your love!"

Us Weekly confirmed last May that the couple, who got engaged in December 2015, were expecting. Chmerkovskiy told Us in September last year that he couldn't wait to be a dad.

"I've been ready since I was like 21," he said. "But now I know that I'm ready, I'm like, 'Thank God it didn't happen before.'"

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