Mr Stern, whose trademark is offensive humour, explained on the show how he had met Mr Evans' ex-wife and planned to bring her with him to the interview and make love to her in front of the ginger-haired millionaire.
"She's spruced herself up since she left you. I said to her I'll make love to you on my lap while Chris watches. There is nothing worse than watching a man, especially a big ugly American like myself, fondle your ex-wife."
He also lambasted Mr Evans for dumping his wife once he got famous - saying Mr Evans could never have got a woman before he became famous.
When he wasn't discussing the former Mrs Evans' attributes Mr Stern, whose American radio show is full of his racism, sexism and homophobia, repeatedly devoted his attention to a black woman in the TFI Friday audience. "I've never had a black woman before," he said. "That black woman is mine."
Mr Stern shut up Mr Evans when he appeared on Stern's radio show two weeks ago and Mr Stern told him he was "a nothing" and to "shut up, you're boring me."
However Evans tried to get his own back with a vox pop in the streets that showed how few people had heard of Mr Stern compared with Mr Evans. Even an American claimed not to know Mr Stern.
However Mr Stern was low key in comparison to his outbursts on his own radio show against blacks, gays, women, Jews - he's Jewish himself - and anything else he comes across.
Mr Stern, 43, is in the UK to promote the film of his life story, Private Parts.
He leapt to national prominence in the US in 1982 after a Miami-bound jet flew into the Potomac river in Washington DC killing 78 passengers. Live on air the next day Mr Stern called the airline and tried to book a one-way ticket to the Potomac Bridge. When told the airline didn't fly to the Potomac Bridge Stern replied: "Well you did yesterday!"
That stunt got him dropped from his Washington station DC101, but he was quickly snapped up on a bigger salary by a New York station.
His humour is based on an obsessional crudeness about sex that titillates ordinarily puritanical Americans and has earned him millions of dollars of fines. It has also earned him a reputed $8m a year.
Regular routines in his radio show include getting porn actresses and prostitutes to strip off and bemoaning the inadequate size of his penis. He once joked about his wife's miscarriage, saying that he had photographed it so his parents could have a photograph of their grandchild.
While Private Parts portrays Mr Stern as an underdog struggling to get his innovative and challenging humour past uncomprehending bosses and bureaucrats in fact his career is based on flashes of occasional brilliance, suffocated by sub-Benny Hill-style pandering to the prejudices of a male, lower-middle class audience worried that it is being overtaken by ethnic minorities and women.
Being American Mr Stern doesn't claim he is being ironic, although his lifestyle is very different from that claimed by his on air persona. He claims to have been faithful to his wife of 19 years and interviewers report that his 6'5" frame, sunglasses and glam-rock hair hides an intelligent and thoughtful man.