The audible gasps and groans seemed to come from every direction of the Outnumbered studio on Fox News yesterday when the rotating cast of four female hosts heard Fox contributor Dr. Keith Ablow deride First Lady Michelle Obama's weight. 

Covering the well-beaten, right-wing media path of denouncing Obama's efforts to improve nutritional habits of American children via improved government standard for school lunches (“She's kind of annoying that way”), Ablow suddenly took the conversation down a bizarre path, even by Fox News standards: He dropped a cavalier, contemptuous and deeply sexist stink bomb by  suggesting the First Lady should “drop a few” if she wanted to be a credible spokeswoman on nutrition: “How well could she be eating? She needs to drop a few. I'm telling you, let's be honest. We're taking nutrition advice from who?”

With both arms sprayed over the middle of Outnumbered's curved couch, a lounging Ablow suggested that because Barack Obama is skinny, he'd be willing to take nutritional advice from him, but not from his (fat) wife who's supposedly sneaking midnight snacks in the White House kitchen.

And with that, the room erupted.

“You did not say that,” responded a stunned co-host Harris Faulkner after hearing the “lose a few” put-down. “Oh my goodness.” Ablow's comment was so crass and debasing Faulkner wondered out loud if the show was “on a seven-second delay” so the weight-loss denigration could be bleeped before it reached the ears of viewers. (It was not.)

And that was the just the beginning. Responding to Ablow, co-host Kennedy quickly launched into an impression of a chauvinist pig (she gave him a thick Brooklyn accent): “Hey Michelle Obama, she needs to lose the junk in her trunk.”

Faulkner again to Ablow: “Oh my goodness gracious.”

Meanwhile, Kimberly Guilfoyle, sitting at the far end of the couch, simply shook her head, and when Sandra Smith tried to continue the nutrition conversation she admitted she was at a “loss of words” following Ablow's abject insult. Yes, Ablow unfurled his sexist, weight-based attack on a program hosted by four professional women.

Soon after, Fox News' senior meteorologist Janice Dean took to Twitter to brush Ablow back even further: “please keep your comments about women 'dropping a few' to yourself. Sincerely, all women.”

The public spat was reminiscent of when ESPN's Michelle Beadle last month condemned colleague Stephen A. Smith, via Twitter, after she watched him suggest that the wife of NFL running back Ray Rice may have provoked the beaten she allegedly received from her husband at an Atlantic City casino.

But that's simply not how Fox News functions; quarrels are almost never aired in public. Remember that when some Fox insiders were deriding Glenn Beck and his increasingly unglued program, chief Roger Ailes laid down the law. “We prefer people in the tent not dumping on other people in the tent,” Ailes told his D.C. bureau in 2010. “I was brought up to defend the family. If I couldn't defend the family I'd leave. I'd go to another family.”

No word yet if Ailes will force Dean to “defend” the Fox News family by standing up for Ablow's transparently stupid, misogynistic attack on Michelle Obama.

But in a weird way, can you blame Ablow? Not for the chauvinist comment. Of course you blame and condemn him for that. But for thinking he could get away with it. For thinking that as long as his target of personal ridicule was an Obama or a prominent Democrat, that it's anything goes. (Ablow yesterday to the Fox ladies, “Join me in my criticism.”)

After all, the unwritten Fox News rule since 2009 has been that no insult is out of bounds when it's launched against Obama or Democrats. Indeed, Fox News represents a safe place for right-wing hate rhetoric to be fermented and fostered.  

And yet with his broadside against Michelle Obama, Ablow managed to trip the nearly invisible wire inside Fox News and crossed over into intramural condemnation. Ablow's attack veered too close to an assault on humanity, on all women, and wasn't targeted enough apparently.

The on-set reaction yesterday was a good thing: A Fox boundary actually exists! 

On the flip side, what took Ablow's colleagues so long? Where was the outrage when he suggested schoolgirls “provoked” harassment by wearing leggings to school? When he claimed Dancing With The Stars will turn kids transgender and that gay marriage will lend to bestiality? When he insisted Obama lacks “Americanism in his soul” and suggested Vice President Joe Biden may have been drunk during his 2012 debate with Paul Ryan?

Fact: Ablow is a menace. Or at least he plays one on TV. And anyone with a conscience who watches him understands that. But that's his Fox niche. That's what he gets paid to do. But on Tuesday, his Michelle Obama insult hit too close to home for the working women of Outnumbered. Maybe they'll remember how that sting felt next time Ablow and his pals unfurl unseemly attacks against Fox's approved list of political enemies.