I recently saw the musical Cabaret, which for those of you who have never seen it, is set in 1930s Berlin. In it, they imply that alternative lifestyles such as homosexuality and polyamory were largely accepted before the rise of the Nazis. Now obviously Broadway plays shouldn't be considered a reliable source, but is there any truth to this portrayal?
Before the rise of Nazism, the Weimar republic had fairly liberal views on homosexualiy e.g. Magnus Hirschfeld & his backing of those that fall in the "gender and sexual minorities" (GSM) categories.
Hirschfeld was a very liberal sexologist and (among other things) helped Einar Wegener transition to become Lili Elbe. Hirschfeld also opened up his Institut für Sexualwissenschaft ("Institute of Sexual Research") in 1919 which advocated for people to have wider education of sexual health which they did by offering classes on various things.
As I'm no expert on this the above is as much as I'm comfortable with saying as I know it's factually correct (however anything more in depth I wouldn't be so confident on) so I'm going to direct you to /u/G0dwinsLawyer who specialises in the Weimar republic & /u/Commiespaceinvader who I'm sure will be able to talk about 1930's Germany.