The second he finished his hosting duties on The X Factor on Monday, the new dad — who also helped launch EXTRA's 20th season at Universal Studios Hollywood and done his radio show, On with Mario, earlier in the day — was ushered out the door to head to the hospital.
Lopez, 39, had received the call: his wife Courtney was ready to deliver the couple's second child.
Twenty minutes after he arrived, Lopez — who greeted the mom-to-be with a kiss before posing for one last quick picture — suited up and was in the operating room anticipating the big announcement.
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"I don't know [what it's going to be]. I don't want to guess!" Lopez, who documented the experience, says when asked his thoughts on whether it would be a boy or girl.
"I think it's going to be a baby! A beautiful, healthy one that hopefully looks just like Mom."
Shortly after, the video shows doctors cleaning off the couple's new son, Dominic, who was born with black curly hair — and a dimple like Dad! "I did it! It's a boy! I did it! It's a boy!" Lopez cheers. "You did it, honey! Way to do it!"