Peta Murgatroyd, Maksim Chmerkovskiy announce they're expecting another boy

Peta Murgatroyd and Maksim Chmerkovskiy have announced the sex of their second child -- and their 6-year-old son played an important part in the reveal.

The "Dancing with the Stars" pros shared an Instagram video in which they start dancing together to "Bounce When She Walk" by OhBoyPrince while Shai slides into the frame and unfolds a piece of paper to show the word "boy" written in his own handwriting.

"It's a…… 💙💙💙," Murgatroyd, who is 32 weeks pregnant, wrote in the caption. "The Chmerkovskiy's as a whole are creating their own soccer team LOL!"

She continued, "We're so elated that Shai will get a baby brother and cannot wait to meet this little guy."

Murgatroyd, who said she and Chmerkovskiy "shrieked with joy" when they found out their baby was "fully healthy," added that he is "already measuring quite large" and "loves to kick mummy in the ribs at all hours of the night."

"We will have a house FULL of boys, including our little Hachi!" she joked, referencing their new puppy. "I guess this means we have to try for baby number 3 to get that girl 🤷🏼‍♀️🙈."

Murgatroyd, who married Chmerkovskiy in July 2017, announced her pregnancy in January after having experienced what she called "constant struggle and heartache" to have a second child.