What is the objective standard for determining the commission of a lewd or lascivious sexual act?

"The application of an objective standard to determine the commission of a lewd or lascivious sexual act is consistent with the requirement that in every crime there must exist a union or joint operation of act (the actus reus) and criminal intent or negligence (the mens rea). [Citation.] This reflects the general principle that a mere intention of the accused to commit a crime or his belief that he is committing a crime, does not give rise to criminal liability. Apart from the mens rea, there must be some act or conduct in violation of law which itself is socially harmful. [Citations.]" (People v. Wallace, supra, [39 Cal.App.4th 1721] 11 Cal.App.4th 568, 579-580, 14 Cal.Rptr.2d 67.)