I spoke to Louise Futcher, a psychotherapist who specialises in issues around sexuality and kink/BDSM, about where these value judgements originate. She identified patriarchy and capitalism as key factors: “Anything that pleases the male gaze and gets straight men off is of course acceptable and desirable, and anything that doesn't fit in with that, such as that which involves female agency and anything perceived to be associated with male homosexuality, is deviant.”Noticeably, then, it’s often acts in which a female partner is the top that are characterised as "abnormal" or strange. Perhaps this is because they don’t fit the same sanitised, gender-stereotypical understanding of kink presented in something like 50 Shades. This inequality was made particularly evident in the recent clampdown on the British porn industry, when government regulator ATVOD began a puritanical campaign to ban the depiction of certain (legal) sex acts from UK pornography - many of which pertained to consensual fetish play and female sexual dominance (Femdom).British Pornographers were told they could no longer legally depict face sitting, certain types of anal penetration, wrestling or fisting – all acts which feature heavily in femdom and queer porn. Female ejaculation was deemed unacceptable, whilst a man coming on a woman’s face remained fine to show. ATVOD disproportionately targeted British sites depicting female dominance and paid far less attention to those showing female submission, suggesting that cultural understanding of "acceptable" BDSM is still predicated along dominant gender lines.Many other kinks that have yet to receive a SATC or 50 Shades PR job are still typified as strange. Despite being common, many of us still view foot fetishes as "gross". It’s seemingly fine to fetishise body parts like breasts or bums, but god forbid someone’s interest should stray south of an ankle. Acts which we think of as dirty or unclean, like golden showers, are also maligned – even though urine poses less of a risk to your sexual health than ejaculate.The point is, there are plenty of kinks out there that won’t float your particular boat, and that's fine. But castigating others for what they happen to like is different. It’s something I often hear in my capacity as a sex worker. A client will ask for a session featuring a particular kink – say, cross dressing and verbal humiliation – but look disparaging when I ask if he’d also like to incorporate some anal play or bondage. “Oh no”, he’ll say, “that stuff’s all a bit too weird”. I can rarely be bothered to point out that other clients of mine would be equally appalled by the acts he happens to find erotic.