It is often said that you cannot consent to being murdered. If you say to someone 'Please kill me' and they do, they can still be tried and convicted for some degree of murder or manslaughter. Furthermore, in many countries, assisting in suicide is also considered a crime, even if the person is fully mentally competent.
Are there any other crimes that youthe victim cannot consent to, in order to prevent them being a crime? It's worth adding that the consent is freely given with no coercion.