There is no line that Bill Maher won’t cross. It is part of what makes him an exciting, unpredictable comedian, and an at times problematic one. His most glaring blind spots concern transphobia—where he shares common ground with alt-right fellow traveler Milo Yiannopoulos—Islamophobia, and casual sexism. Disagree with her politics and shameless opportunism all you want, but repeatedly branding Sarah Palin a “bimbo” is not a good look.

Maher seemed to cross that line again on Friday night.

During an exchange with New York magazine reporter Gabriel Sherman on his HBO program Real Time, the political satirist made an incest joke about first daughter Ivanka Trump and her father, President Donald Trump.

“What do you make of Ivanka and her efforts to sort of humanize her father?” Maher asked Sherman of the first daughter, who is currently flouting ethics rules in promoting her new book, Women Who Work. You see, Sherman has become the leading media voice when it comes to Fox News, and his tireless reporting led to the ouster of Fox News overlord Roger Ailes.

“We see all this misogyny at Fox News, we see it in Donald Trump himself,” continued Maher. “A lot of us thought: Ivanka is gonna be our saving grace. When he’s about to nuke Finland or something, she’s gonna walk into the bedroom and—‘Daddy, Daddy…’” he said, mimicking Ivanka giving her father a handjob. “‘Don’t do it, Daddy.’”

“Is that how you see Ivanka?” Maher asked Sherman. “No,” replied the red-faced reporter. “I think, again, she’s on the margins trying to save us—to the degree that she can—but Donald Trump doesn’t listen to anybody, including his own family.”

It’s not the first time Maher’s told his Ivanka-Donald incest joke. On the night of November 2nd, less than a week before the election, the comedian broadcast his stand-up set from L.A.’s Largo comedy club on Facebook Live. Towards the end of the 45-minute set, Maher addressed the bizarre relationship between President Trump and his eldest daughter. In the past, the POTUS has said that he might “be dating her” if she weren’t his daughter, that he could be sleeping with her if he “weren’t happily married and, ya know, her father” in a Rolling Stone interview, and that time he gave shock jock Howard Stern the OK to call her “a piece of ass.”

Cue Maher: “Be nice to Ivanka, she’s our only hope—because she seems like she actually knows rationality, but she’s [Trump’s] kid, and she’s the only one who can get to him, and you know he loves her,” said Maher. “If he’s going to do something nutty, we’re going to depend on Ivanka going into that bedroom. Daddy”—cooed Maher, mimicking Ivanka giving Donald a handjob—“Daddy, you have to apologize for that tweet where you called Angela Merkela a ‘cunt.’ You have to apologize, Daddy!”

Ivanka Trump is a problematic, puzzling figure, but if liberals are going to castigate Donald Trump for his boorish, sexist behavior, they shouldn’t behave in a similar fashion.