WTF, every generation thinks they invented sex. You think women didn't notice that they got wet when they got horny? How do you think you got here? Your great grandparents got horned up and banged like monkeys, and spawned your parents who banged like monkeys to make you, but you're the one who's got it all figured out.

about 250 years older than that!

1698–1700 [UK] N. Ward London Spy VII: Nor one whore that could have the impudence to ask above Six-pence Wet and Six-pence Dry, for an hour of her Cursed Company.

1832 [UK] Satirist (London) 9 Sept.: [T]he saying has become common, when speaking of what they consider a low girl, ‘Oh! the creature’s wet: she goes to the Piccadilly Saloon’.

1888–94 [UK] ‘Walter’ My Secret Life: Was it not lovely, Charlotte, is not your thing wet?

1920s [US] ‘All Night Long’ in G. Logsdon Whorehouse Bells Were Ringing: We drank one or two as other folks do, / The night was wet, but she got wetter.

1941 [US] in G. Legman Limerick: Her twat would get wet / And would wiggle and fret, / And her cunt-lips would curl and unfurl.

1949 [US] H. Miller Sexus: She was wet as a goose now.

There have always been sexual euphemisms. Media used to be heavily censored, sure, but privately, people were just as dirty as ever.

My great grandpa had a collection of Tijuana Bibles from his time in the Navy in WWII. The horniest comics I've ever seen and chock full of innuendo. My mom found them after he died, along with some homemade smut. I choose not to look at that.

The difference between what was said on TV and what was said in meatspace was much greater back then.

Tell me you've never aroused a woman without telling me you've never aroused a woman.

Bon Jovi's album "Slippery When Wet" came out in 1986

Just as now, back then there was a whole lot of IRL vernacular in existence which couldn't be used in broadcast media.