http://www.independent.co.uk/news/uk/a-long-list-of-sex-acts-just-got-banned-in-uk-porn-9897174.html
The Audiovisual Media Services Regulations 2014 requires that video-on-demand (VoD) online porn now adhere to the same guidelines laid out for DVD sex shop-type porn by the British Board of Film Censors (BBFC).
Seemingly arbitrarily deciding what is nice sex and what is not nice sex, the board has banned the following acts from being depicted by British pornography producers:
Spanking
Caning
Aggressive whipping
Penetration by any object "associated with violence"
Physical or verbal abuse (regardless of if consensual)
Urolagnia (known as "water sports")
Female ejaculation
Strangulation
Facesitting
Fisting
The final three listed fall under acts the BBFC views as potentially "life-endangering".
While the measures won't stop people from watching whatever genre of porn they desire, as video shot abroad can still be viewed, they do impose severe restrictions on content created in the UK, and appear to make no distinction between consensual and non-consensual practices between adults.