Today marks the 39th anniversary of Grease. That’s right, 39 … it sounds like a lot because, to many of us, Grease has always been a thing.

Think of its impact. Most adults know the lyrics to all of the songs (it’s one of the best-selling movie soundtracks of all time). Black leather jackets remain prevalent, flare skirts continue to be popular and Frenchy’s hair mishap is on trend. On top of that, both Gen X and Millennials can reflect on a childhood full of watching movies that featured teens talking about issues which mattered to them—like sex.

In fact, Grease seems to be the first teen sex comedy blockbuster. While not nearly as raunchy as the film that kicked off the 80s teen sex comedy genre, Porky’s (which also takes place in the ‘50s), Grease talks, sings and thinks mostly about sex … just like a normal teen. You may remember:

  • The opening scene shows Danny and Sandy as two kids in love. As Sandy breaks the bad news that she’s moving back to Australia, Danny tries to bed her. Sandy responds by pushing him away: “Don’t spoil it, Danny!”
  • “Summer Lovin’” is all about the locker room talk of teen boys.
  • Danny Zuko and his “greaser” crew sing that the glory of a hot rod is that it’s a real “p***ywagon.”
  • The song “Look at Me, I’m Sandra Dee” mocks virginity.
  • Rizzo sleeps around and has sex with Kenickie without a condom, eventually believing she is pregnant.
  • The “moral” of the story is that in order to get the guy, you need to dress like a slut.

While Netflixing Grease with me, my 22-year old son commented, “Grease: it gets dirtier every time you watch it!’ That’s because, beyond those memorable moments, less remarkable innuendo and vulgarity is also slipped in:

  • Rizzo tells Sonny, Doody and Putzie to get out of Kenickie’s car because “this isn’t a gangbang.”
  • There are lewd hand gestures the T-Birds use to imply sex during “Summer Lovin’.”
  • Marty introduces herself to National Bandstand host Vince Fontaine as “Marty Maraschino … like the cherry”—to which the adult Fontaine reacts and starts giving high schooler Marty and her cleavage quite a bit of attention.

The success of Animal House, also released in 1978, is given credit for inspiring the raunchy teen sex comedy genre, however, Grease demonstrated to studio execs that moviegoers were cool with taking the age level down to high schoolers.

Unfortunately, what didn’t translate to Grease is the Pink Ladies open attitude toward sex. While the girls rib each other about their sexual histories, they don’t do so in a judgmental way. Rizzo jumps in with gusto to sleep with Kenickie, but she never expresses regret or that her sexuality is a result of being “damaged.” Unlike the majority of Hollywood movies to follow, in Grease, the girls are in control of their sexuality.

And now, we arrive at what Grease is actually all about. The film ends in 1959. Grease represents the transition between the repressive “good girl” 1950s that identified Sandra Dee and Doris Day as the role models of taming a man by using sexual restraint—and the “wild” 1960s ushered in by rock n roll, embracing freedom and adventure through sex and drugs. Oh, those magic changes.

So, back to that ending. When Sandy sleazes up her look and language, it does get Danny’s attention. But remember, he’s spent the entire film trying to figure out how he can live up to everyone’s expectations. When he met Sandy, he was the real Danny Zuko—no pretention, no Greaser, no bad boy, no ladies’ man. Once he’s back at school, he feels he has a “reputation” to uphold as the leader of the T-Birds gang—and that persona doesn’t gel with Sandy. So, Danny tries to be a jock to win her heart and shows up at the end-of-school carnival in his athlete’s Letter Sweater. When Sandy makes her entrance—permed, leather clad, and smoking—she is making an effort. In doing so, she demonstrates to Danny that she accepts him as he is.

But, it’s still the girl “changing” to get the guy. The statement Grease is making is that as the 50s came to a close, women were rethinking the confines society put on them, Sandy included. And as Danny and Sandy’s car flies into the sky, it foreshadows the freedom and adventure youth sought in the following decades, where young people rejected the roles put upon them and found comfort in authenticity—including embracing their own sexuality.

From beginning to end, Grease is all about teens and sex. But, unlike Porky’s, The Sure Thing, Losin’ It, Zapped! and the like, Grease actually had something to say.

This is how Grease also paved the way for the other defining 80s genre: the John Hughes film. Writer-director John Hughes took young audiences in a different direction by giving them relatable characters who were dealing with the same concerns they have. While a John Hughes film may include elements of sex or romance, mostly, they were films about the universal experience of high school life: fitting in, class issues, popularity, grades, family, and mostly, trying to find acceptance.

Grease’s longevity lies in a subversive high school story wrapped in catchy tunes with an unexpected ending. Grease’s legacy is that it spurred films being made for teens that reflected their lives and their issues, or at the very least, what they found funny. Over decades, that’s made a deeper dent. Today, youth is the most powerful force at the box office. Grease IS the word.