Section 71 is historically rooted in the Sexual offences Act 1967 which legalised homosexuality and reflected the view of many members of the House of Lords (and arguably public) that whilst they could no longer stand in the way of legalisation of homosexuality (among males) they did not want to risk the chance of encountering a homosexual act.
Although the 2003 Act rendered the offence applicable to both men and women (at least in theory), the offence continues to act as a reminder of a history of shame that has no place in modern legal cultures.
Even for those who continue to be concerned about sex in a public lavatory (which the research by academics such as myself would suggest is unfounded), there is no need for this offence as the common law offence of outraging public decency adequately covers this area.
The full text of the section is included below:
Sexual activity in a public lavatory
(1) A person commits an offence if—
(a) he is in a lavatory to which the public or a section of the public has or is permitted to have access, whether on payment or otherwise,
(b) he intentionally engages in an activity, and,
(c) the activity is sexual.
(2) For the purposes of this section, an activity is sexual if a reasonable person would, in all the circumstances but regardless of any person’s purpose, consider it to be sexual.
(3) 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 level 5 on the standard scale or both