A person (A) commits an offence if—
by means of an inducement offered or given, a threat made or a deception practised by him for this purpose, he intentionally causes another person (B) to engage in, or to agree to engage in, an activity,
the activity is sexual,
B has a mental disorder, and
A knows or could reasonably be expected to know that B has a mental disorder.
A person guilty of an offence under this section, if the activity caused or agreed to involved—
penetration of B's anus or vagina,
penetration of B's mouth with a person's penis,
penetration of a person's anus or vagina with a part of B's body or by B with anything else, or
penetration of a person's mouth with B's penis,
is liable, on conviction on indictment, to imprisonment for life.
Unless subsection (2) applies, a person guilty of an offence under this section is liable—
on summary conviction, to imprisonment for a term not exceeding 6 months or a fine not exceeding the statutory maximum or both;
on conviction on indictment, to imprisonment for a term not exceeding 14 years.