Masculine women, Feminine men

Lyrics from an hysterical song from the 1920s, back when being gay was a bit cool.

Masculine women, Feminine men
Which is the rooster, which is the hen?
It's hard to tell 'em apart today! And, say!
Sister is busy learning to shave,
Brother just loves his permanent wave,
It's hard to tell 'em apart today! Hey, hey!
Girls were girls and boys were boys when I was a tot,
Now we don't know who is who, or even what's what!
Knickers and trousers, baggy and wide,
Nobody knows who's walking inside,
Those masculine women and feminine men!