"My mum is here... she got upset when you dragged up my marriage," said Brand. "I saw her cry. That's the reality because it's real people Graham, that's my real mum.
"I have come here to promote a film and you made my mum cry," he continued, before adding: "I don't see you as that sort of person."
"I don't see myself as that kind of person," replied Norton, but he added that, since Perry had been a guest on the previous week's show, it would have seemed "weird" had he not brought the subject up.
"What I would have done, mate, in your position is come up to me before the show and gone, 'Eh listen, it's a bit odd that your ex-missus was on last week. I might mention it, is that okay?'," the comedian explained.
"But in all of the chatting and the research backstage, no-one mentioned it," he told the audience.