From an earlier answer of mine

Although the Weimar Republic has since the 1930s become somewhat synonymous with decadence and sexual freedom, this experience was far from universal nor was it completely unchallenged. Individuals advocating sexual freedom like Magnus Hirschfeld emerged as public intellectuals in the Republic, it does not necessarily follow that their advice seeped into everyday practice. Nor were all sex reformers as radical as Magnus Hirschfeld, most mainstream German sexologists emphasized healthy sexuality as a function of marriage, not sexuality for its own sake. Public celebrations of sexuality and other "decadent" pastimes generally tended to shrink once outside urban centers like Berlin. Even in Berlin, avenues of sexual escape and alternative experiences tended to be the exception rather than the rule to daily life in Germany's largest metropolis.

Berlin during the Weimar period certainly did have an outsized cultural weight compared to earlier periods, with emigres like Nabokov of Josephine Baker living in the city and a number of German intellectuals like Brecht. With regards to sex, there was a general loosening of morals in terms of semi-public entertainment. Cabarets and other venues did feature female nudity and other transgressive forms of entertainment. Some of this entertainment tried to fit into the forms of the neue Sachlichkeit (new objectivity) that sought to break with the stuffy norms of the Kaiserreich and the prewar avant garde. Dadaism, for instance tried to create art without real boundaries or conventions and some Dadaists thrived in Berlin's hustle and bustle. Yet, not all of these sensual entertainments were done in the name of neue Sachlichkeit and a number of them were peep shows or nude reviews with only a thin veneer of artistic pretensions.

One of the reasons why these shows became more prominent was the general loosening of the Kaiserreich's censorship laws under the Weimar Constitution allowed more freer expression in clubs or other venues. Yet this did not mean all forms of vice were now legal. Female prostitution remained in a nebulous position it had prewar where it was technically illegal, but loosely regulated by the Sittenpolizei (morals police) or other municipal authorities. Laws passed in 1927 further decriminalized female prostitution, but also kept a regulatory function. Some women abided by these rules, whereas others were free agents. The decriminalization actually made life harder for these women as it gave the police much greater powers to crack down on streetwalkers and other sex workers who were not registered. The overall system of female prostitution was highly exploitative sex work in most cases with a good deal of corruption among the regulators. Homosexuality remained illegal under Paragraph 175 of the legal code and there was no real regulation of male prostitution. Weimar Berlin certainly did develop a gay subculture in certain areas of the city, but this often built on precedents set during the Kaiserreich. There were gay clubs in the late Wilhelmine era that operated as open-secrets with municipal authorities and regions of Berlin like Friedrichstadt already had a reputation by 1914 for being the area to cruise for male prostitutes. Part of what fueled this development was the simple fact that Berlin was Germany's megalopolis. The explosive growth of the nineteenth century not only allowed for an anonymity that was not possible in smaller cities like Frankfurt am Main, but also provided a steady base of young men who were out of work and could turn to prostitution to make ends meet. The dislocations of war and its aftermath only added to these trends.

The city itself was far from a safe-haven for LGBTQ people. Weimar Berlin did witness periodic police raids against homosexual bars and sweeps of transvestite and homosexual prostitutes. German courts would also periodically declare some publications to be obscene, and the often right-leaning judges had little problem condemning publications like the lesbian-themed publication Frauenliebe. Hirschfeld was not only notable for his arguments that homosexuality was a normal form of sexual expression, but also because he was one of the few voices in Germany publicly arguing this position. Most mainstream Weimar sexologists still treated homosexuality as a disease or disorder that was unhealthy. Much the same fate befell the few researchers that examined transgender issues and transvestism ; the basic assumption was these behaviors and preferences was that they were a deviation from a heteronormative order and should be examine as such. Nor was all of Weimar's sex culture necessarily politically progressive in nature. Weimar's various discourses about the body and nudism often betray a profound concern over racial degeneration, strict militarization and regimentation of nudes, and an association of the health of an individual's body with that of the wider health of the nation. Many of Hans Suren's bestselling nudist books have völkisch overtones and celebrate an aesthetically pure Germanic body type.

Weimar Berlin also became one of the epicenters for what Germans at the time called the "New Woman" who wore cosmetics, bobbed her hair, and had a new can-do attitude to life and sexuality. Appearances of women's new independence though were often quite deceptive. Even though the New Woman was a reality for many Germans, beneath the glitz and glamour of Weimar fashion was a sexual dynamic that was often quite disadvantageous towards women. While the showgirls of Berlin's cabarets symbolized a the new objectivity and openness, at the end of the day they were still very much objectified cogs in an entertainment machine. Moreover, new fashions and a modern lifestyle were expensive habits. In a very perceptive 1931 article "Twilight for Women?, Hilde Walter noted that beneath the weight of advertisements for the modern woman was an actual mass of working women who were underpaid and had to now shoulder the extra expense of appearing "modern" to keep their jobs. In her estimation, liberation often entailed a new set of burdens as onerous as the pre-Weimar femininity.

German references to modern German womanhood in print could be quite condemnatory and these attacks often spilled over into condemning her sexual profligacy and un-German materialism. Especially in the Catholic south and Protestant countryside, the New Woman became a symbol for much of what was wrong with Germany's Republic. Walter's essay also noted that attacks on the new woman ran the gamut of the left and right, which underscores another aspect of sexuality and Weimar: its politicization. The most prominent advocates for sexual reform like Hirschfeld prominently connected sexuality with wider political reforms and they tended to be partisans of Germany's left. The Austro-German Wilhelm Reich, one of the most radical of the Republic's reformers, argued that sexual repression served the interests of capitalism and other social injustices. Yet the affinity of sexual reformers for the German political left was often quite one-sided. The Weimar KPD was somewhat stuffy and conservative. The KPD newspaper Rote Fahne decried Dadaism and other experimental art forms as mindless decadence and most mainstream KPD thinkers associated Berlin's sexual tourism and prostitution as a vices of a capitalism that commodified everything

Right-wing German commentators castigated figures like the sex journalist and raconteur Hugo Bettauer as a puppet of the KPD and other left-wing figures. The NSDAP's paper Völkischer Beobachter relished in tales of Weimar decadence as part of an overall stratagem to discredit the Republic as unGerman. This highly politicized atmosphere surrounding sex helped propagate the impression of the Weimar Republic as a freewheeling Bacchanalia, when it was in fact much more complex. Julia Roos's research into research into statistics kept by the Sittenpolizei and other agencies has found that actual numbers of prostitution did not explode in urban areas despite the contemporary panic surrounding them. The NSDAP certainly trafficked in associating Berlin's decadence was a consequence of the city's red-leaning politics, but this was only one arrow in its attacks against the Republic, but one whose charge has unfortunately stuck in the public consciousness since 1945. Sexual experimentation and experience was a real Berlin subculture in the Weimar period, but it never was a dominant culture and was usually on the cultural fringes of the metropolis.

Sources

Herzog, Dagmar. Sex After Fascism: Memory and Morality in Twentieth-Century Germany. Princeton, N.J.: Princeton University Press, 2005.

Jensen, Erik Norman. Body by Weimar: Athletes, Gender, and German Modernity. Oxford: Oxford University Press, 2010.

Large, David Clay. Berlin. New York: Basic Books, 2007.

Marhoefer, Laurie. Sex and the Weimar Republic: German Homosexual Emancipation and the Rise of the Nazis. Toronto: University of Toronto Press, 2015.

Roos, Julia. Weimar through the Lens of Gender: Prostitution Reform, Woman's Emancipation, and German Democracy, 1919-33. Ann Arbor: University of Michigan Press, 2010.

Sutton, Katie. The Masculine Woman in Weimar Germany. New York: Berghahn, 2013.

Weitz, Eric D. Weimar Germany: Promise and Tragedy. Princeton, N.J.: Princeton University Press, 2007.