Mario Lopez Shares Baby Picture on 40th Birthday

Hey there, good lookin'! Mario Lopez celebrated his 40th birthday on Thursday, Oct. 10, by sharing a photo of himself as a smiling, chubby baby in the ultimate Throwback Thursday post.

"Going way back for #TBT almost 40 yrs ago… Here's my little fat self back in the day," he captioned the black-and-white photo, in which he shows off some impressively chunky arms and his trademark deep dimples as a tiny tot.

These days, the Extra host has likely been busy documenting his own little bundle of joy. He and wife Courtney Lopez welcomed their second child, Dominic Lopez, in Los Angeles on Monday, Sept. 9.

PHOTOS: Saved By the Bell: Where are they now?

"It's a boy!!!!!!!!!! Please welcome Dominic Lopez to the world," the hunky TV host tweeted at the time. "Couldn't be happier… Courtney & baby are doing just fine."

The happy couple are also parents to daughter Gia, 3.

PHOTOS: Shirtless hunks!

Back in February, after the pair announced their pregnancy news, the X Factor host told Us that he had been secretly hoping for a boy. "I already have a girl, so if we have a boy that would be nice," he told Us. "But I won't be disappointed if we don't."