It’s a boy for Jessica Simpson! The singer gave birth yesterday via Caesarean section to her second child with fiancé Eric Johnson, a baby boy named Ace Knute Johnson. Ace is the second child that Simpson and Johnson have together; she gave birth to a baby girl named Maxwell Drew Johnson in May 2012. A spokesperson for Simpson said that mom and baby “are doing great” and that “Jessica, Eric and Maxwell are thrilled to welcome the new addition to their family."

Simpson confirmed her second pregnancy via Twitter last Christmas Day and revealed her planned baby name back in February, but hasn’t confirmed why she chose Ace as a name. However, it’s likely that the name is a family tribute of sorts. The baby’s unique middle name, Knute, came from her husband’s Swedish paternal grandfather, Knute Johnson. The name of Simpson’s daughter, Maxwell, is Johnson’s middle name and was her grandmother’s surname. Maxwell’s middle name, Drew, is Simpson’s mother Tina’s maiden name.

Jessica Simpson 2 Jessica Simpson at the panel for NBC show "Fashion Star," January 2012

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The singer had planned to keep the sex of her second baby under wraps when she first became pregnant, but accidentally spilled the beans when talking about morning sickness in an interview last March on Jimmy Kimmel Live! “The crazy thing is I never knew a wiener could make me nauseous — well, I guess I just told the world that I’m having a boy!” she laughed. She previously described motherhood in a September 2012 interview with Katie Couric as “a dream” and “absolutely amazing.”

Simpson and Johnson, a former NFL player, began dating in May 2010 and became engaged six months later. They are reportedly planning a wedding set to be held at the end of this year. Simpson was previously married to 98 Degrees member Nick Lachey, but the couple split in June 2006 after nearly four years of marriage. Johnson was also previously married, but his then-wife Keri filed for divorce in January 2010 after gossip site TMZ caught him cheating with Simpson.

Jessica Simpson Jessica Simpson at the Kennedy Center Honors, December 2007

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Simpson is currently serving as a mentor on NBC reality competition Fashion Star. She’s also continuing to build her clothing line, the Jessica Simpson Collection, which includes a line of maternity wear and children’s clothing. In early 2011, the company became the first ever celebrity clothing line to break $1 billion in sales.