Justin Bieber and Wife Hailey Welcome a New Puppy into the Family Named Piggy Lou: 'Baby Sister'

Justin Bieber/instagram

Justin Bieber and Hailey Baldwin Bieber are proud parents of a new puppy!

The Grammy-winning singer, 28, and the Rhode founder, 25, introduced their family's latest addition — a cute pup named Piggy Lou — in a series of sweet photos on Instagram on Monday.

Bieber debuted the family of four in a carousel via Instagram on Monday. In the first snap, he holds his and Baldwin Bieber's two doggies, Piggy Lou and Oscar, who joined the family in 2018.

The Biebers are in full Halloween mode as Bieber is dressed as Sesame Street's Cookie Monster and Baldwin Bieber channels her inner sultry vampire.

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In another photo, Bieber sweetly cuddles with Oscar as the singer makes a sentimental face for the camera, following up that picture with one of Oscar showing off his cute face.

Bieber marked the occasion with the caption, "Happy Halloween 📸: @amberasaly"

Baldwin Bieber also unveiled Piggy Lou to the world in her Instagram Story.

She held up the pup, who was wearing a fitting piggy costume, and wrote over the adorable photo, "This is Oscar's new baby sister Piggy Lou Bieber."

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She and Piggy Lou later have a sweet moment as she holds the dog up to her face in another snap, simply captioned, "Piggy Lou"

Piggy then showed off her modeling skills as she posed on a couch wearing a floral and polka-dot bandana as a collar.

"PIG," the model wrote across the picture.

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The new addition comes after Bieber and Baldwin Bieber celebrated another occasion: their 4-year wedding anniversary.

The pair, who secretly wed in September 2018, marked this year's milestone with sweet posts on Instagram.

The Canadian singer shared a black-and-white selfie of him and his wife laying next to each other with an adorable puppy in between them.

"Happy anniversary to my best friend and wifey @haileybieber .. thanks for making me better in every way," Bieber, 28, captioned the Instagram post.

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Echoing the same sentiment, Baldwin Bieber, also shared a sweet Instagram post featuring a carousel of images of the couple.

"4 years married to you," she wrote in the caption. "The most beautiful human I've ever known... love of my life. Thank God for you. 🤍🥂."

One snap shows the couple sharing a kiss at their South Carolina wedding ceremony, held almost one year after they tied the knot in a New York City courthouse, featuring Baldwin Bieber's veil that read "Till Death Do Us Part."