Thompson Square's Shawna and Keifer Thompson Welcome Their First Child -- Find Out His Unique Name!

by Elizabeth VanMetre and Emily Krauser 2:35 PM PST, January 24, 2016
Playing Thompson Square's Shawna and Keifer Thompson Welcome Their First Child -- Find Out His Unique Name!

The country singer duo, Thompson Square, has officially become a trio!

Keifer and Shawna Thompson welcomed their first child, a son, on Sunday, their rep confirms to ET.

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Their brown-haired, blue-eyed baby was born at the wee morning hour of 2:46 a.m. CT in the Nashville, Tennessee-area. They've named their bundle of joy Rigney Cooper, with Rigney being Shawn's grandmother's maiden name.

Photo: Thompson Square

"We're so excited to be able to share this monumental day with all of you," Thompson Square told ET in a statement. "We've had many wonderful things happen to us but this absolutely tops them all. We want to thank you all for being there for us and our music and for all of your support during our pregnancy. We can't wait to see you out on the road this year but until then... Please say hello and welcome to this big ol world, Rigney Cooper Thompson aka #coopert #cooperman #coopdeville #coopdog #sircoopsalot."

How cute is it that the Thompsons' little man already has all those nicknames?!

Just two weeks ago, Shawna, 37, shared a photo on Twitter of her growing baby bump.

“38 weeks and two days as of today! Little Cooper will be here before we know it,” she captioned the pic.

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The "Are You Gonna Kiss Me or Not" singers wed in 1999 and will celebrate their 17th wedding anniversary in May. They announced they were expecting their first child in August with an adorable Instagram photo that showed the pair drinking out of Coke cans labeled "Dad" and "Mom," then revealed the baby's gender one month later.

WELL……WE HAVE DECIDED NOT TO BE A DUO ANYMORE!!!!!!! #Jan2016 #T3 #WeDidIt #BabyOnBoard

A photo posted by thompson square (@thompsonsquare) on

Another singer welcomed a son this week. Michael Bublé's wife gave birth to their second son, Elias, on Jan. 22. Get all the details on the GRAMMY winner's growing brood in the the video below.