Female ejaculation is something that can, in England, make an otherwise R certificate porno illegal.
In England, explicit consensual porn is legal, as long as it doesn't include various things including golden showers. The British Board of Film Classification apparently recently refused certification to a film called Squirt Queens, featuring lots of ladies, well, squirting. Apparently the Board had been told by the police that, as female ejaculate can or does contain urine, as far as they're concerned female ejaculation in a film constitutes a golden shower, and any film containing such would be treated by them as illegal porn, wether it was given an R certificate or not.
Bureaucracy in action.