Jessica Simpson remained adorable and candid in a sitdown with Jimmy Kimmel to promote 'Fashion Star,' and she revealed more than she bargained for -- including the sex of her baby -- in her typically charming, foot-in-mouth fashion.

When Kimmel asked Simpson how her second pregnancy is going compared to her first with baby girl Maxwell Drew, Simpson accidentally spilled the beans about the baby's gender.

Simpson talked about how often she's been vomiting (lovely) before blurting out, “The crazy thing is I never knew a weiner could make me nauseous.”

Wait, what? Oscar Mayer foodstuffs? Her fiance Eric Johnson's johnson?

No. Her baby's weiner, she expounded: “Well I guess I just told the world that I’m having a boy!" she laughed. "I can’t believe I just did that, that was not planned … I just did it so crude, I feel awful!”

Simpson and Kimmel chatted about naming her baby Ace, but she wouldn't outright confirm or deny it: "Let's just hope I'm having a boy!"

The former 'Newlyweds' star previously hinted on 'Ellen' that Maxwell would have a baby brother, but 'Jimmy Kimmel Live' had her first outright confirmation of the status of her bambino.

As for marriage plans with Johnson, Simpson explained that she'd love to walk down the aisle, but she "keeps getting knocked up." (Psst. Jess. There are ways and means to prevent that.)

“Maybe I should go back to when I was younger,” she mused. “I was a virgin before I was married, so maybe I should just completely reverse and just stop having sex all together until Eric and I actually say, ‘I do.’”

We think that's incentive enough for him to call the caterers and florists.

Watch Jessica Simpson Pick Out Onesies on 'Ellen'

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