California Code, Penal Code - PEN § 314

1. Exposes his person, or the private parts thereof, in any public place, or in any place where there are present other persons to be offended or annoyed thereby; or,

2. Procures, counsels, or assists any person so to expose himself or take part in any model artist exhibition, or to make any other exhibition of himself to public view, or the view of any number of persons, such as is offensive to decency, or is adapted to excite to vicious or lewd thoughts or acts, is guilty of a misdemeanor.

Every person who violates subdivision 1 of this section after having entered, without consent, an inhabited dwelling house, or trailer coach as defined in Section 635 of the Vehicle Code, or the inhabited portion of any other building, is punishable by imprisonment in the state prison, or in the county jail not exceeding one year.

Upon the second and each subsequent conviction under subdivision 1 of this section, or upon a first conviction under subdivision 1 of this section after a previous conviction under Section 288, every person so convicted is guilty of a felony, and is punishable by imprisonment in state prison.