We're deep. Don't be ashamed of reading us, say Jilly and Joanna

On a perfect May evening - as the sun set and her juices stirred - Jilly, a multimillionaire author in immaculate chiffon, walked arm in arm with her dear friend Joanna to face an adoring thousand-strong audience. Joanna, of course, was as rich as Jilly - perhaps even richer - but she did not have Rupert Avington-Hartsmere waiting in bed, just for her. And this time, he was wearing riding breeches.

Or, at least, that is how the author herself, Jilly Cooper, might have described her entrance, with Joanna Trollope, to a sell-out encounter at the Hay-on-Wye literary festival. Cooper, Britain's unofficial Poet Laureate of Post-Menopausal Sex, was candid on her perceived literary failings. "There are two categories of writer. Firstly, there's Jeffrey Archer and me, who long for a kind word in The Guardian. And then there's the others, who are forever being praised in The Guardian but who long for mine and Jeffrey's sales."

Trollope considers the lack of prestige accorded to her and Cooper's works to be a symptom of "Britain's inherent Puritanism ... We feel we shouldn't enjoy things, especially reading, and we feel guilty if we do. But if something is frightfully grimy and black and makes you want to jump down a well - you know, 'grim lit', I call it - then we feel we're being improved by reading it."

The authors gave a rare insight into their working methods. "I talk to myself all the time when I'm writing," Cooper explained. "At the moment, I've got East End black people in my head [because they are the focus of her next work]. They sound dreadfully like upper-class people in the country right now, but it'll get better." Her forthcoming, as yet untitled work, is set in a school, "because my characters are all getting on a bit so I was worried I was losing the younger end of my readership. So I'm writing about their larky children."

The novel, she said, was a departure from her previous work because "I've got paedophiles and lots of black people and September 11 in it". The son of one of her most-loved and lusted-after characters, Rupert Campbell-Black, is a lead character. "He's black and adopted and at school with white children," Cooper explained. "There are lots of black children in schools now and they're having a terrible time. I'm a campaigner, really."

Trollope described her own recent topics as "death and cows", although she was shocked by her research in this area. "Having worked with the cows, I couldn't believe how nasty they are to each other. If there's a weak one, the other cows will go and stamp on her head. It's just beastly, beastly."

She also described a meeting with Martin Amis. "It was two or three book festivals ago, and I was sitting in my room. Well, you can see that I'm tall, and I opened the door when there was a knock and I found this immaculate, tiny little man standing there. He said, 'Excuse me, I'm looking for Stephen Fry,' and I said, 'Well, I haven't got him.' And he apologised an awful lot and then left."

The session proceeded in this faintly surreal, rambling way, with Cooper describing "a bell-ringer I know", who was now banned from working with children on his own because of our current "ghastly" national paedophile hysteria. She also revealed that she has "a marvellous, marvellous dog in my new book. He's called Partner, because he's owned by a single woman who's always being asked if she's got a partner, and once she's got the dog, she can say yes."

Trollope loved this idea. "From now on, I shall refer to Max [her pet dog] as my partner. I'll tell journalists I've got a wise black partner at home with a passion for dustbins. That'll sort the Daily Mail, won't it?" But somehow, it was clear that the audience hoped this was a clever ruse, and that she really had a Rupert Avington-Hartsmere in riding breeches waiting on her bed ...