I owe the Legislature of Pennsylvania an apology. The phrase "ultimate sexual act" is not an example of poor legislative drafting. Instead, it copies word for word the language of the Supreme Court in Miller v. California:
We emphasize that it is not our function to propose regulatory schemes for the States. That must await their concrete legislative efforts. It is possible, however, to give a few plain examples of what a state statute could define for regulation under part (b) of the standard announced in this opinion, supra: (a) Patently offensive representations or descriptions of ultimate sexual acts, normal or perverted, actual or simulated.
I still contend it makes little sense, but the Legislature just followed exactly the language of the decision.