If a person (“A”), who has attained the age of 16 years, with A’s penis, penetrates to any extent, either intending to do so or reckless as to whether there is penetration, the vagina, anus or mouth of a child (“B”), who—
(a)has attained the age of 13 years, but
(b)has not attained the age of 16 years,
then A commits an offence, to be known as the offence of having intercourse with an older child.