Draxz said:
Also, what would your view be on not telling the other that you had/have an STD/STI? Would that make it a form of rape? Is there any cases on that or other?
The UK, as far as I'm aware, has no specific offence for rape by deception.
However, not disclosing that you have HIV (it may extend to other STDs, but I've only heard of it in the context of HIV) means that your partner cannot offer informed consent to any activity which might put them at risk of HIV infection.
I suspect it's one of those areas which hasn't come up yet, and were it ever to do so then whoever was presiding would probably try to use the common law system to reach an equitable result in practice. Long term, that would probably result in the law being changed.