Simpson revealed that she's having a boy!
She was talking about how much she's been vomiting this time around, in comparison to her relatively easy first pregnancy, when she blurted out, "The crazy thing is I never knew a wiener could make me nauseous!"
"Oh, shush!" she swatted at Kimmel when he burst out laughing. (Move over, Eric Johnson. We absolutely love your fiancée, too.)
Asked what she might have intended to say, Simpson admitted, "Well, I guess I just told the world that I'm having a boy!"
"Oh, I didn't even know what was happening! Maybe you were having a girl with a penis, I don't know!" Kimmel shrugged. "Well, congratulations."
"Thank you," Maxwell's adorably flustered mom replied. "I'm sweating now!"
Noting that the tabloids got it right when they reported that Simpson planned on naming her first child Maxwell, Kimmel asked if they were right-on again with reports that she might name her second baby Ace.
"Let's hope it's a boy!" Simpson exclaimed, before admitting, "I kind of just outed that I'm having a boy right? I can't believe I did that! That was not planned."
And, as Simpson has so gleefully admitted on talk show after talk show, the gender reveal hasn't been the only surprise.
(Originally published March 6, 2013, at 9:57 p.m. PT)