If someone gains sexual consent by lying about themselves it...
some context, and some more details of the police doing this. But there are plenty of examples of non-police doing it.
Obviously, this can be a huge grey area - and I'm not asking about what the law _is_, but about what you think the law should be.
Also, I know that this is a massively emotional area, please try and phrase things in an understanding and non-combative manner. People may well have opinions very dissimilar to your own, and I'd rather that they felt ok to express and discuss them without being bounced on unpleasantly.