Sexual Offences Act 2003.
Section 68 Voyeurism: interpretation
(1) For the purposes of section 67, a person is doing a private act if the person is in
a place which, in the circumstances, would reasonably be expected to provide
privacy, and—
(a) the person’s genitals, buttocks or breasts are exposed or covered only
with underwear,
(b) the person is using a lavatory, or
(c) the person is doing a sexual act that is not of a kind ordinarily done in
public.
i rest my case!