A person aged 18 or over (A) commits an offence if—
for the purpose of obtaining sexual gratification, he intentionally causes another person (B) to watch a third person engaging in an activity, or to look at an image of any person engaging in an activity,
the activity is sexual, and
either—
B is under 16 and A does not reasonably believe that B is 16 or over, or
B is under 13.
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 10 years.