3-Month Mark! New Mom Peta Murgatroyd Celebrates Son Shai's Monthly Milestone with Sweet Snap

He's growing up so fast! Shai celebrates his 12-week birthday milestone on April 5.

Hitting 3 (months), and as cute as can be!

Peta Murgatroyd commemorated her son Shai Aleksanders age milestone with a sweet new photo on Wednesday.

In the image, Shai whose father is Murgatroyd’s fiancé Maksim Chmerkovskiy held tight to a sign that read, “Today I am twelve weeks old.”

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I39;m officially obsessed #3monthsold #babychmerkovskiy

A post shared by Peta Murgatroyd (@petamurgatroyd) on Apr 5, 2017 at 8:18am PDT

The onesie-clad baby boy was cozied up to an oversized stuffed elephant. Wrote Murgatroyd, 30, “I’m officially obsessed #3monthsold #babychmerkovskiy.”

Shai wasn’t the only one celebrating a milestone: Grandpa Chmerkovskiy turned 57 on Tuesday!

The Dancing with the Stars pro, 37, shared a photo of his father Aleksandr Chmerkovskiy holding tight to Shai, writing, “Birthday Boys! 57 years young OG and 3 months old YG! #GrandpaSwag #babyChmerkovskiy.”

Wishing Daddy a speedy recovery from La La Land We love you and can39;t wait to get you back Kisses from Shai XO

A post shared by Peta Murgatroyd (@petamurgatroyd) on Mar 29, 2017 at 5:44pm PDT

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Both Murgatroyd and Chmerkovskiy were competing on this season of the reality dancing competition before the latter was sidelined with a calf injury.

Chmerkovskiy’s partner Heather Morris is still competing with a replacement partner, Alan Bersten, as the star isn’t certain when or if - he’ll be able to return to the show.

“Please rest assured that I’m taking this thing very seriously and, although I don’t have a concrete return date, I’ll give it my all!” Chmerkovskiy captioned a late-March Instagram post.

This article was originally published on PEOPLE.com