None but those whose courage is unquestionable can venture to be effeminate

From Strange Flowers blog:

The key to Firbank’s life as well as his art is a sense of never quite belonging. He was born into wealth but it was only two generations old and thus socially suspect. His delicate health led him to constantly seek out more sympathetic climes, and his friends knew of his comings and goings largely from notices in The Times. He was also a Catholic convert, like Waugh in the following generation and Frederick Rolfe in the previous...[though he was] rejected from the priesthood and ever after maintained a strange, Oedipal love-hate relationship with Catholicism.

All of these things, as well as his homosexuality, gave Firbank a privileged vantage point to observe the rituals of his circle as well as its hostility to outsiders, but the barbs in his writing are sometimes so subtle that they only become visible on a second reading. While his plots and dialogue can occasionally seem as precious and overstuffed as a Victorian salon, Firbank was also remarkably forward-looking, such as in the impressionistic passages in Valmouth which record fragments of conversation, out of context, or his regular deployment of characters who were gay or lesbian or otherwise alienated.

Some examples of these are neatly summarised in the GLBTQ Encyclopaedia:

In the utopian world of Valmouth (1919), an imaginary health resort presided over by the black masseuse Mrs. Yajnavalkya, the characters engage in an intricate arabesque of secret amours and are eventually revealed to be gay, lesbian or bisexual.

After the war, Firbank further developed the theme of gay-lesbian utopia in his one-act play, The Princess Zoubaroff (1920), which creates a pastoral "green world" of homosexual freedom and explores the advantages of social arrangements in which the sexes live apart. The happy, middle-aged Lord Orkish is Firbank's portrait of the Oscar Wilde who might have been had Wilde gone into exile rather than facing his persecutors in England.

His last and most explicitly gay work, Concerning the Eccentricities of Cardinal Pirelli, appeared in 1926, the same year as Firbank's early death at the age of forty. The book begins with the cardinal baptising a police puppy named Crack, and ends when the naked cardinal ("elementary now as Adam himself") drops dead while pursuing a choirboy named Chicklet around his church.

Excavating the homosexual meanings in everything from St. Sebastian to Egyptian statuettes, butterflies to orchids, and Priapus to Ganymede, his use of inverted word order, dashes, exclamation points, ellipses, and innuendo shows his characteristic "Sapphic" mode of presenting material in fragments in order to articulate the love that dares not speak its name.

His description of Monsignor Parr in Vainglory as "something between a butterfly and a misanthrope, [who] was temperamental, when not otherwise...employed," gives some indication of his masterful use of indirection.

Committed to the preservation of gay and lesbian culture in an era of political backlash, as well as to the unfettered expression of his artistic self, Firbank himself may be fittingly characterized by the comment of Lady Parvula de Panzoust in Valmouth that "None but those whose courage is unquestionable can venture to be effeminate."

There are numerous accounts of Firbank’s personal eccentricity, such as presenting the Marchesa Casati with a bunch of lilies and suggesting that they embark immediately for America, sending his cab driver to smooth the way before his first meeting with Augustus John, or his unlikely participation in sports. While at Cambridge, Oscar Wilde’s son Vyvyan Holland recalls seeing the effete Firbank incongruously dressed “in the costume of sport”. Confounded, Holland enquired what he had been doing, and learning that he had apparently been playing football, further enquired whether it was rugby or soccer. “Oh,” replied Firbank, “I don’t remember”.

Nancy Cunard recalls a meal in London in 1922:

"A charming, but at that moment insufferably drunk, young man was with me and we were about to have dinner. Noisily and lengthily captious at the menu’s many suggestions, he had finally reached the point of announcing ‘I’ll have…I’ll have a…’ while the waiter stood by looking more than weary. At that moment Firbank swept in, ecstatic, and came dancingly towards us. As I tried to introduce them my companion scowled at him, muttered something about ‘fairies’ and reached the end of his thought: ‘A beefsteak’. ‘And what with, sir?’ asked the waiter. ‘What with, what with?’ groaned the angry man, ‘with…’ Firbank stood poised above us. With a swoop over the table and an ingratiating giggle he suggested clearly and winningly: ‘Try violets!’"

"The world is so dreadfully managed, one hardly knows to whom to complain."

"To be sympathetic without discrimination is so very debilitating."

Arthur Annesley Ronald Firbank (17th January 1886 – 21st May 1926)