I don't know what it is, but songs about 16- and 17-year-olds are incredibly creepy. Probably because they are obviously sung by men far too old to be hitting on or to be with teenage girls. Here's a fine playlist of of some "hits" about teenage girls:
Enjoy the creepy pinkness of this widget.
1. "You're Sixteen You're Beautiful (and You're Mine)" Johnny Burnette--Why is it so creepy: an obvious fascination with childish and little girly things like ribbons and curls. Also, putting a girl on a pedestal proving that he's not really into talking to her/finding out if she has a personality.
2. "Sixteen Candles" The Crests--Why is it so creepy: emphasizes the youth of the subject (the birthday girl) and wishes for reciprocated love even though he's probably about ten years older. Ew.
3. "Only Sixteen" Sam Cooke--Why is it so creepy: Actually, this one isn't creepy because it's sung from the perspective of a 16-year-old boy. In fact, it's rather sweet (16?). I just included it to break up the grossness.
4. "I Saw Her Standing There" The Beatles--Why it is so creepy: "You know what I mean."
5. "Seventeen" Foreigner--Why is it so creepy: Assumes a girl of 17 is capable of playing games with someone's heart in some sort of mature manner--although she was probably trying to get out of this controlling/emotionally abusive relationship.
6. "Seventeen" Winger--Why it is so creepy: I owe the discovery of this song to Pajiba's "The Dark Age of Metal." Just watch the video in that post and be creeped out by the hairy creepiness of 20-something rockers hitting/preying on 17-year-olds.