You expect Jimmy Carr to be offensive. That is the ticket you knowingly buy. But even by his standards, one moment in his live show left the room teetering between laughter and stunned silence - myself included. I saw his Jimmy Carr: Laughs Funny's tour in Austin, Texas, as part of my husband's 40th birthday celebrations, fully prepared for the kind of razor-sharp, no-topic-off-limits humour that has made him one of the most controversial (and hilarious) comics on the planet. What I did not expect was a routine that openly addressed why he treats different religions differently - and did so with brutal, unapologetic honesty.

At one point, the 8 Out of 10 Cats host paused and casually announced: "No, we are a little bit tight for time, so I'm not gonna do my Islamic bit." The audience immediately erupted in chants for him to continue. What followed was a brutal admission delivered in that trademark deadpan tone that makes it impossible to tell whether you should laugh, wince, or both. "Well, obviously!" he said.

"Obviously, I'm not gonna be telling the same jokes about Mohammed that I feel very comfortable telling you about Jesus Christ. That's because, fun fact, I'm not a f*****g idiot."

There was a split-second pause - then a wave of shocked laughter rolled through the theatre. Carr did not back down. If anything, he leaned in further.

"So if you're a Christian, and you're sitting there thinking, well, that's not fair. He makes jokes about Christians all day long, but he won't make the same sort of joke about Muslims, well then maybe as a Christian you should think about blowing something up."

"No one's scared of you. What are the Christians gonna do? Forgive me?"

The punchline detonated. Some people howled, others gasped. A few began looking around to make sure it was OK, laughing. It was exactly the kind of polarising reaction Carr has built his career on provoking.

Love him or loathe him, Carr's entire brand is built on the premise that comedy should be dangerous.

He has long argued that stand-up is one of the few places where taboo subjects can be explored precisely because the audience has chosen to be there. No one is ambushed. No one is forced to listen. If you don't like it, you can leave.

Critics say jokes like this cross the line. Fans say he's just saying what everyone else is too scared to.

The theatre was packed, and tickets weren't cheap - nobody walked in blind. Carr's reputation for controversial jokes has followed him for years, and while he has issued the occasional public apology, he rarely backtracks, explains or softens the punchline. He simply moves on, as if dropping a conversational grenade is just another beat in the act.

The 53-year-old veteran funnyman has built a career on saying the unsayable. In Austin, he proved he still knows exactly how to do it - and exactly how far he can go before the room stops breathing.

Maybe the real problem isn't the jokes - it's that we've forgotten how to laugh. If everything becomes off-limits, there'll soon be nothing left for comedians to joke about at all.