The Brassic actress and Mark expressed their glee after his brother, Josh, welcomed his first child with wife Hollie earlier this week. The 31-year-old shared his happy news on Instagram, revealing that the couple are now proud parents to a beautiful baby boy after he was born four weeks early.
WATCH: Mark Wright and Michelle Keegan's love story in pictures
New mum Hollie also shared her joy over the "unexpected surprise", revealing that her son was born in the early hours of Tuesday morning.
Posting several heart-melting photos of the tot on Instagram, it wasn't long before Hollie and Josh's family reacted to the sweet snaps, including Michelle, who gushed: "Utter perfection. So happy for you both. Xxxx."
Mark also shared a beautiful image of him and Michelle doting over the new addition to the family, with the caption: "Welcome to the world little man…. Auntie, Uncle and everybody loves you so much. My nephew…. Just stick with me son and everything will be alright."
Mark and Michelle look so in love with the newborn
He added: "So proud of the way you have both handled this early surprise @joshwright4444 @holliekanewright love you both so much.
Josh posted several of the same photos of the newborn on Instagram, including one of Hollie holding her son moments after giving birth, writing: "OUR BABY BOY, 00.55 am, 22.2.22, 5lbs 9.
"A complete surprise and unexpected arrival earlier in the week that has truly changed our lives for the better and forever."
Josh shared the first adorable photos of his son on Friday
He continued: "It's taken us time to post and share our special angel because of how shocked and overwhelmed we have been but I don't say this lightly 'he is truly the best thing that has ever happened to us and the proudest moment of my lifetime'.
"I love and care for him more than words can explain and I simply never realised, knew or understood the feeling I got the minute he arrived and will never be able to explain it.
Josh and Mark are very close
"My wife Hollie is a warrior, hero, superstar and soldier to say a few and the journey we went on this week is one that will live in our minds every day for the rest our lives and I can't thank her enough for producing our wonderful son."
Josh added: "4 weeks early but 4 more weeks of loving my new best friend that I can't wait to see grow into a fit, healthy, happy gentleman that I will try to guide through life just like my Mum and Dad as well as family did with me.
"Welcome to the world son I promise to be the best Dad there possibly could be. Love you unconditionally and all I have left to say is THANK YOU."
Like this story? Sign up to our HELLO! Mail newsletter to get other stories like this delivered straight to your inbox.