I think the easy answer is to ask yourself, "What is a 14 yr old allowed to read/watch/listen to?":
- Playboy/Penthouse, probably not; Maxim, Stuff, FHM (perhaps suggestive poses but I don't think any nudity), okay
- R-rated movies (on personal DVD), 14yr couldn't watch them, but any PG or PG-13 movies (some of which I assume could have brief nudity), ok
- adult music (ie. perhaps an unedited version of Emimem), no, but other music yes.
If the 14yr can legally buy it, then I don't think you could complain to someone who might we reading/watching/listening to it around you.
Jeff