Perusing the Internet I found this article coming from a Brazilian newspaper in São José do Rio Preto (which is a middle size town located in the North-East of the state of São Paulo).
Here is my (rough) translation of the article:
A WOMAN SPREAD POISON IN HER VAGINA IN ORDER TO KILL HER HUSBAND DURING CUNILINGUS
Last week, an unusual occurrence was recorded in Rio Preto's 4th Police District. It concerns an investigation for attempted murder. What is unusual about this story is the nature of the complaint: a man went to a cop and told him that after a fight with his wife she put a toxic product in her vagina and ask him to perform cunilingus on her.
Nimble, the husband smelled the product before tasting the poison and he became suspicious of the intention of the wicked woman. The complaint was recorded by the police officer Walter Colacino Jr., who - given the unusual version - ordered an investigation of the details of the affair before taking any action.
From now on, I'll never have sex after a fight with my girlfriend.