The Backstreet Boys star revealed on Instagram that his wife, Rochelle Karidis, is expecting a baby girl. The duo is already parents to four-year-old Ava Jaymes.
"Out of the millions of pics I've either been in or taken of my two loves my wife and my daughter nothing will ever ever ever amount to this one pic," he wrote next to a photo of Ava kissing her mom's belly. "This is what life is about and this is love at its best."
He continued, "Ava baby your [sic] gonna be the best big sister in the world and I cannot wait to see you and your Lil sister side by side. I'm so proud as a father to be able to be present and so in tune with my family."
The couple announced the pregnancy on Labor Day with a photo showing four pairs of Air Jordan sneakers. "So the McLean family will be expecting a new addition to the family next spring!!!" the 38-year-old wrote at the time.
Congrats to the soon-to-be family-of-four! Scroll through the gallery below to see more of the best pregnancy announcements of 2016.
1 of 16
Ciara and Russell Wilson
They're expecting their first child together.
2 of 16
Shay Mooney
The musician and his fiancée welcomed a baby boy named Asher James in January.
3 of 16
Blac Chyna and Rob Kardashian
She welcomed their first child, daughter Dream, on Nov. 10.
4 of 16
Olivia Wilde and Jason Sudeikis
She welcomed their second child, daughter Daisy Josephine, on Oct. 11.
5 of 16
Christy Carlson Romano
The former Even Stevens star welcomed a baby girl named Isabella Victoria on Christmas Eve.
6 of 16
Nick and Vanessa Lachey
They welcomed a son named Phoenix Robert on Christmas Eve.
7 of 16
Kevin and Danielle Jonas
She welcomed their second child, daughter Valentina Angelina, on Oct. 27.
8 of 16
Rob Dyrdek
His wife gave birth to their first child, son Kodah Dash, on Sept. 9.
9 of 16
Alec and Hilaria Baldwin
She welcomed their third child together, son Leonardo Ángel Charles, on Sept. 12.
10 of 16
Kris Allen
His wife gave birth to their second child, daughter Rose Elizabeth, in June.
11 of 16
Alexa and Carlos PenaVega
They welcomed their first child, son Ocean, on Dec. 7.
12 of 16
Jurnee Smollett-Bell
She welcomed her first child, son Hunter Zion, in November.
13 of 16
Megan Hilty
She's expecting her second child.
14 of 16
Alison Pill
She welcomed her first child, daughter Wilder Grace, on Nov. 19.
15 of 16
Alex Gerrard
She's expecting her fourth child.
16 of 16
Ryan Lochte
His fiancée, Kayla Rae Reid, is expecting their first child.