I do enjoy a good musical--especially one about union organizing (NEWSIES!)-- so when I found out the plot of The Pajama Game (1957) (union gal and superintendent fall in love in the midst of a fight for higher wages at a pajama factory, spunky white employees sing a lot of songs about love and then a couple about getting better pay) I was obviously interested.
So let's look at what gender relations looked like in 1957:
Doris Day tells the ladies why she's not in love, addresses the silliness of rumors, but it's also pretty obvious that she's going to fall in love with him in a minute. (This is a trend in musicals that I don't like, because I get all hopeful about the "empowering" songs that the "feisty" female lead sings, and then it turns out that in the next scene all those words have gone down the drain. Ughhh. But they're still fun while they last.)
Vernon Hines gets a lesson on trusting his hottie girlfriend and policing her sexuality? Sort of.
Is she playing hard to get, or is Sid trying to pressure her... ? Also, they started dating like, earlier that day, so it's weird that they're saying "I love you," even in Musical World. Props to Babe/Doris Day for sticking to her union-guns.
Love is a very heterosexual thing in the musicals of 1957.
Gladys takes lead in this song/dance number and cross-dresses. (Fun fact: the movie was choreographed by Bob Fosse, who was the inspiration for the choreography in Beyoncé's "Single Ladies," so some of the choreography looks very similar.)
Babe has an ideology crisis that is largely influenced by her romantic troubles. Y do boiz make eVeRyThInG so HARD?
Fortunately, Sid takes up union interests and investigates further because his "life depends on it." Not life as in his monetary life, but his love life. His investigation into the mystery of union raises involves getting a secretary drunk. (Side note: I went to a musical theater camp as a child and we did this song... it is not appropriate for middle schoolers! What were they thinking? Actually, this movie is sort of littered with inappropriate jokes about consent and sex and abuse.)
And they get their 7.5 cent raise! Surprise! Sid and Babe get married. Surprise! It's a silly movie, but amusing, and a 50s musical precursor to other, more serious movies about union struggles.