I'm not sure how it started, why it happened or who started it... but some sexy and BDSM-type styles have turned hipster. There are phases, like owl tattoos and looking like a starving lumberjack with giant 70s sunglasses and a handlebar 'stache. I'm not judging style-followers as fall for the occasional "She's wearing that, I wanna wear that" too.
This phase (if it is a phase at all) is different than a simple tattoo, it's actually saying something about yourself. I'm seeing more and more young fellas walking around with a leather collar and no goth-gear. Christina Aguilera demonstrates her sexual openness in her latest video Not Myself Tonight where she shows off her dominance with costumes, sex toys and by, well, dominating various lucky video extras. Not to mention the orgies!
Another example of sexual openness accross the pond is Lily Allen's Not Fair. The video is irrelevant but the lyrics are about this poor girl who has this amazing partner but he's selfish and no good in bed. She's quite explicit about lying alone in the wet patch on the bed and about giving head.
All this to say that it's great that celebs are helping out the community by being open about lifestyles and issues regarding sex. Younger people are realizing what's out there early and that it's okay to want to stuff a sock in someone's mouth, throw them on the floor then do "naughty" things to them. These celebrities are telling you that you are not alone!
All I ask, hipsters, is that you do not cover your owl/random bird tattoo with a leather-bound kittykat stuffed with a ball gag.