The doting mum and the songwriter sandwiched their baby boy between them as they went in for a hug and cradled their son.
Little Elias gave a slightly confused, serious look at the camera, endearing fans to the picture even more.
Michael Bublé and Luisana Lopilato welcomed their baby boy in January
Luisana, 29, explained in her native Spanish that it was her birthday so she could "sleep at whatever time" she wanted. The Argentinean model was pictured closing her eyes in the Instagram snap, while Michael, 40, beamed at his son.
The Haven't Met You Yet singer also paid tribute to his wife on Instagram, sharing a photo of the couple with their older son Noah, who turns three in August.
The singer regularly shares photo of his children on social media
"Happy birthday, Feliz cumple @luisanalopilato!!" he wrote. "You've changed my life and there are no words to describe how proud you make me every day. Thank you for choosing me."
Michael also threw his wife a surprise birthday party, as Luisana shared a photo from their festivities. "I'm so lucky to have you in my life... you make me feel so loved, every single day," she wrote.Luisana and Michael are also the proud parents to two-year-old Noah
The pair got engaged in November 2009 and in March 2011 they married in Luisana's native Buenos Aires.
The couple regularly show off their two adorable boys on social media. Luisana recently posted a photo of herself lying in bed with her brood. "This is how I look after four hours of sleep," she wrote. "But being surrounded by so much love makes me forget everything!"
Michael also recently used Instagram to apologise for bowing out of upcoming events, because he is due to have vocal cord surgery. "No talking or singing for awhile but my doctors expect a complete recovery," he explained.