Hey, I sang that to my girlfriend the day she turned 16. I was the same age. She’s now 64 and we’re still married, and it’s one of “our songs”.
Hey, Screamin’ Jay fans get an enormous release from that song.
Speaking of cringeworthy songs, way back when we had a coal-black guinea pig named Black Betty. She was the consort of a cavy named Eno.
Is the other one When I’m 64?
indeed that’s another one of our songs now.
Paul McCartney primarily — and he was, like, what, 19 when they started writing it?
Though I have had the perverse thought of what if in 1998 there would have been a collab on stage between Macca and B. Spears on that track, just to make people extraordinarily uncomfortable.
Neil Diamond - Girl, You’ll be a Woman Soon
According to this article (which is quoting the book The Beatles: A Hard Day’s Write — The Stories Behind Every Beatles Song) Paul came up with the line “She was just 17 / Never been a beauty queen” but neither Paul or John really liked it, so…
John came up with the lyric “She was just 17/If you know what I mean.” Paul said the new line could be seen as innocuous or provocative. After all, 16 was the age of consent in England at the time. Even years later, the song still provoked controversy. According to the BBC, Jerry Seinfeld once told Paul “‘Just Seventeen, you know what I mean’? I’m not sure we do know what you mean!”
Speedy Gonzales, Pat Boone
Don’t Go Near The Eskimos, Ben Colder
It still is!
But if you do, emphasize the self-defence aspect.
Pfft. ZZ Top has them both beat. Their “Francine” just turned 13!
Turning from sex to violence we have this little gem Burton Cummings threw together while with the Guess Who. The song is obviously supposed to be a parody/homage to 50’s rockabilly, but it got a little out of hand.
I’ll kill your kid sister, I’ll murder your dad
I’ll rip the lashes off your eye,
I’ll slaughter all your cattle and I’ll burn your crops
If you’re dancin’ with another guy.
I always thought David Bowie’s China Girl was kind of cringeworthy, but I guess Bowie’s parody of racism went over my head. 
In the studio version of the Rolling Stones song Stray Cat Blues, about an underage groupie, there’s the line “I can see that you’re just 15 years old”. Then in the live version on Get YerYa-Yas Out, they change the age to 13. As if 15 is not gross enough. Yeah, it may not be a capital crime, Mick, but it’s still a very serious crime.
On Bob Seger’s Live Bullet album, at one point he segues into a bit of Chuck Berry’s song 'Little Queenie". He changes the Chuck Berry line from “Too damn cute to be a minute over 17” to 13. Ewww.
Lot of icky underage references in 60s-70s rock.
In Rod Stewart’s Every Picture Tells A Story are the lyrics
Listen, on the Peeking ferry, I was feelin merry
Sailing on my way back here
I fell in love with a slit-eyed lady
By the light of an eastern moon
Really tough to get past that line.
I despise Billy Idol’s “White Wedding” for lots of reasons, but the fact that it’s clearly about incest doesn’t seem to keep stations from playing it.
It’s not, from everything I’ve read, though of course you’re still allowed to despise it 
So “little sister” is just a pet phrase for a woman he wants but isn’t related to? Or is it actually his sister, but he’s urging her to marry someone else? Please fight my ignorance!
Okay, it does seem to be about his sister marrying someone else. And yet:
Idol added, “Then I thought about this incestuous kind of sick brother…"