The Crown Prosecution Service had previously listed torture and bondage, among other acts, as obscene.

Distributing that type of pornography either on or offline could therefore have led to a prosecution.

But the CPS has now removed the list and replaced it with series of "tests" that determine whether an image or video is classed as obscene.

https://www.bbc.co.uk/news/technology-47069414

According to

https://www.cps.gov.uk/legal-guidance/obscene-publications

owning or producing pornographic material is unlikely to be prosecuted if:

it features consenting adults, where the provision of consent is made clear where consent may not be easily determined from the material itself
no serious harm is caused, whether physical or otherwise
it is not otherwise linked with other criminality
the likely audience is not under 18