The expectant mother shared a pic of her baby bump and even revealed the sex - another baby girl!
Simpson's main career now is running her brand, Jessica Simpson Collection - a line of clothes, shoes, handbags and beauty products.
"My good buddy Jessica Simpson and I are gonna sing a song together", Nelson told the crowd before Simpson joined him on stage to sing a new song, "I Will Be Your Fool". "I mean, we're very happy and we know how to make babies very well, but we got the little one here".
"I have two handsome children, and I'm not having a third", she continued. "We had an IUD", Simpson insisted, referring to a birth control implant.
Although the star revealed previous year that she had an IUD and was done having children, it appears she's had a change of heart. "But it would definitely have to be a miracle". Last year, she joked to Ellen DeGeneres, "I'm not pregnant on your show!"
But while they appreciate their alone time, she couldn't help but brag about how much of an unbelievable father Johnson is.
'Right now my kids are in this fantastic stage where I'm really listening to them without judgment and they're teaching me so much'.