A person generally commits the criminal offense of public lewdness or lewd conduct in public if the person knowingly engages in any of the following acts in a public place—or, if not in a public place, the person is reckless about whether another is present who will be offended or alarmed by the person’s (1) act of sexual intercourse; (2) act of deviate sexual intercourse; (3) act of sexual contact with a person’s own private parts or those of another.

Public lewdness laws vary from state to state, and some states define and charge such criminal offenses under indecent exposure laws. Public lewdness is usually a misdemeanor offense, but may be a felony offense under some circumstances. And in some states a conviction for public lewdness may require the defendant to register as a sex offender.

In California, the criminal offense of public lewdness is typically referred to as 'lewd conduct in public' and is governed by California Penal Code Section 647(a). This statute makes it a misdemeanor for anyone to engage in lewd or dissolute conduct in any public place or in any place open to the public or exposed to public view. This includes acts of sexual intercourse, deviate sexual intercourse, and touching of the private parts either of oneself or of another person. The law requires that the conduct must be done with the intent to sexually gratify oneself or another person, or to offend, and that the person must have known or should have known that another person who might be offended by the conduct was present. A conviction for lewd conduct in public does not typically require registration as a sex offender in California, unless the conduct involved certain aggravating factors such as involvement of minors or repeat offenses, which could fall under different sections of the law and potentially require registration under California's sex offender registration laws.