Noice Marines my boy, turn people inside out with the power of Rock! Ain't nothing faggy with that and you know that the Slaneesh boys get plenty of groupies, some of them even have the normal amount of appendages!
The guy who made goatse would worship Slaanesh. End of argument.
Disco Marines, I'm guessing their favorite is Barbie Girl by Aqua, would explain the destructive powers of their sound blasters.