@IwantToRetire It all gets very complicated.
"I didn't know, and seems strange if the law says at 16 you can give consent.
So would that be statutory rape?"
Just to go off on a bit of a tangent. When it comes to sex, just ordinary consensual sex, if a child is under 13 then it is a "strict liability" offence and the other person has no defence.
However, if the child is between 13 and 16 then the other person does have a defence if they can show that they "reasonably believed" that the child was at least 16. Although, of course, if it was non-consensual then it is rape.
This does happen. There was a case reported in The Guardian a few years back concerning a star from the TV show "Dragon's Den". He was charged with having sex with a girl under 16 but he made the case that since they had met on an "adult" type of website which was meant for over 18s only that he reasonably believed that she was over 16 and he was found not guilty.
https://www.theguardian.com/uk-news/2016/jan/29/former-dragons-den-panellist-doug-richard-cleared-of-child-sex-offences
"Sections 25 and 26 Sexual Offences Act 2003 create ..."
"I cant quite get this but am quite tired."
There are two different things going on here. Section 25(1) reads:
(1) A person (A) commits an offence if—
(a) he intentionally touches another person (B),
(b) the touching is sexual,
(c) the relation of A to B is within section 27,
(d) A knows or could reasonably be expected to know that his relation to B is of a description falling within that section, and
(e) either—
(i) B is under 18 and A does not reasonably believe that B is 18 or over, or
(ii) B is under 13.
So, A has to "intentionally" touch B and it must be "sexual".
Then the family relationship has to be one that is included in Section 27. This includes a whole range of different scenarios but definitely includes grandparent/grandchild.
Then with age, there is a strict liability if the child is under 13. If the child is between 13 and 17 then A must "reasonably believe" that they are at least 18 otherwise it is an offence. The burden of proof of this lies with A.
The Explanatory Notes to the Act give this following example:
"[52] A has never met the child before, and so does not know, and could not reasonably be expected to know, that she is his sister, and reasonably believes she is over 18, he will not commit this offence by engaging in sexual activity with her, even though she is in fact his sister, and only 14."
Section 26 is the same but covers "inciting" so there doesn't even need to be any touching.
"Sections 64 and 65 Sexual Offences Act 2003 make..."
This is the confusing bit. Section 25 & 26 are there to cover the older relative, A.
But Sections 64 & 65 also say that, in the above cases, if B is 16 or older and agrees to penetration then they are also guilty of an offence, but not if they are under 16.
The penalties are a lot lower in this situation. For an adult convicted under Sections 25 or 26 the maximum sentence is 14 years. A child has a maximum sentence of 5 years.
But under Sections 64 & 65 the maximum sentence is 2 years.