Hmm. Makes me reflect on my own music-listening/sex-indulging history:
At puberty/14, I was really into Janet Jackson's semi-dirty new album (the self-titled one, in the early 90s) and was thinking all kinds of sexual thoughts. But I had been thinking sexual thoughts for a long time, long before I hit puberty. Had things continued on that path, who knows... I probably would have been barefoot and pregnant within a few years.
At 14, though, an evangelical Christian friend told me that it was bad to listen to that kind of music... and that friend ended up converting me. I guess I felt guilty at some level, since she hit a nerve there. It was Christian music (with a smattering of classic rock) from that point until I was well into my college years... at an evangelical university, where everyone listened to Christian music anyway. Very few of us were having sex, I can tell you that. But the music only enhanced the effect of the social rules... that was the whole point of the music. To keep us from "going astray" and thinking about bad things like sex.
Classic rock grew on me, but due to my engagement with evangelicalism, I never really thought about sex until my early 20s. Around that time, I started rocking out to more sexual classic rock songs that amused me and also made me... think about sex.
(e.g. You shook me all night long, Feel like makin' love, etc.)
But it would be hard to say what influenced what... I mean, once I got out from the oppression of Christianity on my sexuality, I was more open in general to listening to sexual music and thinking about having sex. I wouldn't say one was a direct cause of the other. In any case, by my mid-20s I was having sex and enjoying it. And still enjoying sexual music. But I think that had more to do with my personality and stage in life than anything else... the music complimented where I was at.
All that said, having spent most of this summer listening to the top-40 hip-hop and urban music channels... I'm actually pretty shocked by how blatantly sexual the lyrics are (especially by men). I mean, it doesn't offend me, and I'm quite happy in my monogamous relationship
and it gets me horny when I'm at work listening to it.
But... if I was 14 again, not religious, not in a committed relationship, had hormones raging through my body, and everyone around me was doing it... shit, the music would push me right over the edge. This stuff makes Bad Company sound like Sesame Street.
So, the music is an influence, definitely. A cause? Probably not. There isn't a lot of direct causality in social science, anyway. But I don't think the music helps teens make responsible sexual decisions, fo' shizzle.