I've seen a lot more of that "little black dress" thing in RPF femmeslash fandoms. In the fandom for Morning Musume (a Japanese girl group), there were a few LBDs (but not a lot of fanfiction. As in most Japanese fandoms, fanart and fanvideos are more popular, and there are tons of them). I've read some Girls Aloud (a British girl group) fan fiction, and that fandom was very happy to pair up the girls in any combination, but generally centered on Cheryl Cole.

I wonder if the LBD's in RPF fandoms has to do with how with these pairings, one does not have to rely on males creating females, but with females taking charge of themselves. They are real people, so they are bound to have their own qoals and quirks come out. Granted, with most pop music acts there is a little bit of acting that might be thought out by a male manager or producers, but for the most part, these women are their own person. There is generally more material to work from too.