Use the Data Protection Laws
The data protection principles already cover this:
Fair collection: no secret filming,
Use of personal data: consensual bedroom shots assumed to be for private enjoyment of participants*
Duration of retention: Not kept longer than necessary. When the relationship ends, the original purpose (shared enjoyment by participants in the relationship) has ended, so the data must be destroyed*.
Security: protection from unauthorised access. If you're keeping the pics, it's your responsibility to make sure they don't "accidentally" leak onto the internet
* unless there is another agreement.
There are grey areas (topless beach is a public place, but a deserted beach plus a telephoto lens?), and things to be worked out (can you secretly film, then ask for consent?), but it fits, and simply brings more personal data under the same protection.