While running on the beach, this song plays, suggesting that Danny and Sandy are in love… or at least the closest to love that two teenagers on summer vacation can get.
SANDY: Danny, is this the end?
DANNY: Of course not. It's only the beginning.
It's hard to tell if Danny believes that their love will last after they part, or if he's just telling Sandy this because he knows it's what she wants to hear. Considering how Danny acts next, it wouldn't be unfair to assume that Sandy thinks she's in love and is sad that she has to leave, while Danny will brush it off like sand from his legs.
SONG LYRICS: They think our love is just a growing pain. Why don't they understand? It's just a crying shame.
The lyrics for "Grease" (is the word) capture what it's like to be a teenager. Some people may doubt that they truly know what love is, but in that moment, their feelings are more real than anything else. Not understanding that is a crying shame.
DANNY: Summer lovin' had me a blast. […] I met a girl crazy for me.
The "Summer Nights" song is insanely ambiguous. The way Danny sings it, it's hard to tell if it's about love, or sex, or both.
KENICKIE: I'll make an honest woman out of ya.
It seems like Rizzo and Kenickie's relationship is based purely on lust, but Kenickie steps it up when he finds out that Rizzo is pregnant with his baby. He's a good guy and maybe, just maybe, he loves her just a little bit too.
DANNY and SANDY: You're the one that I want.
For a film that begins with "Love is a Many Splendored Thing" we don't get to see many of those splendors until the end. In fact, for most of the movie, our starred couple is broken up. But at the end, they finally commit to loving one another—and the T-Birds and Pink Ladies all pair off too.