Notwithstanding any provision of law to the contrary, it is no defense for an offense or sentencing provision defined in this title or in Title 16 or 31 which has as an element of such offense or sentencing provision the age of the victim that the accused did not know the age of the victim or reasonably believed the person to be of an age which would not meet the element of such offense or sentencing provision unless the statute defining such offense or sentencing provision or a statute directly related thereto expressly provides that knowledge of the victim's age is an element of the offense or that lack of such knowledge is a defense.