The Hollywood Code in 1934 banned any reference to a long list of subjects, including homosexuality.
Filmmakers got around the code by marketing their work as 'public service' films. One example is the cheap exploitation film, Sex Madness, produced in 1938.
The film includes plenty of creepy guys at burlesque shows making faces like this:
And of course, warned us all about the horror that is Syphilis.
In one scene Peggy attempts to seduce her innocent coworker Betty:
Watch the whole scene: