Joy gave birth to their new bundle of joy on Sunday, September 12, 2020.
The now mother of six said this birth was a "totally different experience" compared to her first five deliveries.
Joy had so much "fear and anxiety" that she "couldn't stop crying."
"It was my first time to be alone, without @giansotto by my side," she said.
"But grateful for my doctors and the nurses as well who helped calm me down.
"And of course, I Praise God for HIS comfort and peace upon me from delivery to recovery."
Gian, for his part, still felt like a first-time dad. He said in his own Instagram post: "Grabe, pang anim na beses ko na maging Tatay pero feeling ko first time parin..."
The couple has yet to reveal their son's name.
This boy is the second baby the Sotto clan welcomed into the family this month.
On September 7, 2020, Gian's cousin Paulina Sotto gave birth to her daughter Sachi.
Gian and Joy announced their pregnancy in April 2020.
They have five more kids: Hugo, 15; Edrigu, 13; Rossano, 7; Sancho, 8; and their unica hija, Amari, 4.