"Jessica Simpson's baby boy has a new playmate! The Fashion Star mentor's BFF, CaCee Cobb, gave birth to her first child on Thursday, Aug. 15, a source tells Us Weekly. "Yesterday @caceecobb and I welcomed the most amazing little boy into our lives! Oh Happy Day!!" proud father Donald Faison tweeted on Friday, Aug. 16. New mom Cobb retweeted her husband's message with a little addition of her own: "The happiest day of my life." PHOTOS: The cutest pictures of celebrity kids This is the first child for Cobb, 35, and Faison, 38, who is also dad to four kids from previous relationships. Married since December 2012, the couple first announced that they were expecting on Jan. 31, with a Facebook photo of a tiny T-shirt featuring a baby-sized Star Wars stormtrooper. "Looks like Donald Faison and I are going to have a little stormtrooper of our own!" the first-time mom captioned the adorable snapshot. "We're over the moon!" she added a few days later, in a message thanking fans for their well-wishes. PHOTOS: Celebrity pregnancy confessions Indeed, Faison couldn't be happier about his fifth little bundle of joy. "I'm just excited for CaCee," he told Us Weekly in February. "She's probably the most loving person I've ever met in my life." He added: "And so for her to have a baby that she can love and you know, raise, and that we can raise together, and she can influence and teach and stuff like that, it just, I know that it'll be a really good human being when it's older." PHOTOS: Sexy celeb dads Cobb's special delivery comes just a month and a half after the birth of her BFF's baby boy, Ace Knute Johnson, whom Simpson and fiance Eric Johnson welcomed via scheduled C-section on June 30. Ace is Simpson's second child; she and Johnson also have a daughter, Maxwell, born in April 2012. This article originally appeared on Usmagazine.com: CaCee Cobb Gives Birth, Welcomes Baby With Donald Faison!"