Mayberry defense of good faith belief in consent applies to charge of misdemeanor sexual battery. Andrews was tried on numerous offenses including rape, the lesser included offense of assault with intent to commit rape, and misdemeanor sexual battery. An instruction regarding defendant’s good faith belief in consent was given as to the rape and assault with intent to rape charges but not as to the misdemeanor sexual battery charge (People v. Mayberry (1975) 15 Cal.3d 143). The jury acquitted Andrews of the greater sexual offenses, but convicted him of misdemeanor sexual battery as well as several other unrelated felonies. On appeal he claimed the Mayberry instruction should have been applied to the sexual battery. Held: Reversed. A Mayberry defense has both subjective and objective components. A defendant must honestly and in good faith believe that the complainant consented to sexual intercourse and his belief must be reasonable under the circumstances. The offense of misdemeanor sexual battery includes the touching of an intimate part of another person against his/her will (i.e., without the person’s consent), for the purpose of sexual gratification. As the underlying rationale for a Mayberry defense “is that under section 26, reasonable mistake of fact regarding consent is incompatible with the existence of wrongful intent,” the defense applies to misdemeanor sexual battery. Here, there was substantial evidence to support the instruction. Noting the California Supreme Court has not yet determined whether in such cases a Chapman or Watson prejudice standard applies, the court found that, under either standard, reversal was appropriate.