"‘Lying together’ meant that a man placed his stomach against a woman’s and that it was a crisis when he warmed her"

Biography may have little to tell us about why a novelist writes well, but it can sometimes be helpful in understanding why a novelist writes badly. So it is not insignificant, in reading such a purple passage, to learn that at the time he wrote it--in his mid-twenties--Forster actually did not know how men and women had sexual intercourse. This is hard to credit, but Forster himself said so.

-- Adam Kirch, reviewing a new biography of E.M. Forster.

... I wrote long ago on Forster's Aspects of the Novel with regard to why he quit novel-writing. Kirsch:

Moffat argues, with support from Forster himself, that the reason he stopped writing fiction was his impatience with heterosexual romance as a subject. But Forster also gave other reasons--above all, his sense that the novel was intimately connected with a social order that was doomed in Europe.

My guess was closer to Moffat's, but not so predicated on "heterosexual romance." Forster just found the novel tedious. In Aspects he complains that the novel must tell a story, and I think he simply came to dislike the creaky causation of the traditional novel, without caring to strike off into experimentation like Woolf's. Consider his recurrent tendency to authorial digressions; Forster was perhaps an essayist trying to write novels. If the man had really burned to write gay novels, he could've gone expat and lived in happy homosexuality in the south of France or wherever. I think he really came to recognize that it wasn't in him.