Lack of Consent
In any Article 120 prosecution alleging a child victim, lack of consent is not an element. That the victim may have consented or that the accused mistakenly believed the victim consented is not an affirmative defense.
In Article 120 prosecutions involving non-children, lack of consent is an element only with respect to Wrongful Sexual Contact (MCM, Part IV, Paragraph Para 45b(13)). That offense purports that contact was "without the permission" of the alleged victim. Other than the above offense, the government is not required to prove the victim did not consent unless an affirmative defense is raised.
When the evidence raises that the victim consented for an offense - rape, aggravated sexual assault, aggravated sexual contact or abusive sexual contact - the government must prove lack of consent.
If the evidence raises that the accused mistakenly believed the purported victim consented for an offense, the government must prove the accused either was not mistaken OR that the mistake was not reasonable.