Broadcaster and writer Stephen Fry has tried to establish himself as an unlikely authority on female sexuality, claiming that straight women only go to bed with men "because sex is the price they are willing to pay for a relationship".

In uncharacteristically extreme comments, the openly gay Twitter champion said he believed most straight men felt that "they disgust women" as they "find it difficult to believe that women are as interested in sex as they are".

"For good reason," he declares in a candid interview in the November issue of Attitude magazine. "If women liked sex as much as men, there would be straight cruising areas in the way there are gay cruising areas. Women would go and hang around in churchyards thinking: 'God, I've got to get my fucking rocks off', or they'd go to Hampstead Heath and meet strangers to shag behind a bush. It doesn't happen. Why? Because the only women you can have sex with like that wish to be paid for it."

Fry, 53, continues: "I feel sorry for straight men. The only reason women will have sex with them is that sex is the price they are willing to pay for a relationship with a man, which is what they want," he said. "Of course, a lot of women will deny this and say, 'Oh no, but I love sex, I love it!' But do they go around having it the way that gay men do?"

The remarks denote a marked break in tone from a man whose public shtick tends towards inoffensive charm and gently upmarket wit and are likely to be roundly dismissed by those who have embraced the idea of women's ability to have unemotional, uncommitted sex as an empowered lifestyle choice.

Rosie Boycott, the journalist and feminist, said the remarks were "kind of rubbish. Women are just as capable as men are of enjoying sex. We don't go cruising or cottaging on Hampstead Heath because we don't need to. Cottaging on Hampstead Heath is presumably a hangover from the days when, sadly, [homosexuality] was illegal… Women have other ways to get our thrills, and we can go and get them in bars or clubs. Having said which, we probably also do it in parks sometimes too. It's just that we don't call it cottaging. I'm sure I've done it in parks in my time."

Paul Flynn, the journalist who spoke to Fry, said: "I thought it was quite an odd generalisation to make at the time, but he delivered it with certainty and it was clearly something he'd thought about."

The theory has left several commentators bemused. Susie Orbach, the psychotherapist and feminist campaigner, said she was interested in the wider implications of Fry's beliefs: "I'm really intrigued by his notion that men's sexuality is disgusting in some way. Why would he believe that women could be so disgusted by men? Does he think there is something disgusting about sex?"

For Flynn, the bewilderment sprang more from a homosexual man's belief in his authority on female sexuality. "Gay men debating the whys and wherefores of female sexuality… for very obvious reasons, we can hardly claim to be experts," he said. "I'm more interested in his feeling that straight men are somehow to be pitied. That's quite a radical standpoint."

Fry's theory that straight women use sex as a currency in their pursuit of romantic love appears to run contrary to the wider movement to destigmatise – or "de-slut" – ideas surrounding sexually active females. The trend has gained ground over the past decade with characters such as Sex and the City's Samantha Jones owing their popularity to a fondness for no-strings, anonymous sex – and lots of it.

Fry is in a relationship with 25-year-old actor Steven Webb. In the interview, he also speaks with frankness about his experiences in the "extraordinary underworld" of cottaging in his youth, cautioning, however, that while he was "slightly obsessed" with the clandestine practice as a teenager it was more for the graffiti and sense of solidarity.