“(A) Contact between the penis and the vulva or the penis and the anus, and for purposes of this subparagraph contact involving the penis occurs upon penetration, however slight; (B) contact between the mouth and the penis, the mouth and the vulva, or the mouth and the anus; (C) the penetration, however slight, of the anal or genital opening of another by a hand or finger or by any object, with an intent to abuse, humiliate, harass, degrade, or arouse or gratify the sexual desire of any person; or (D) the intentional touching, not through the clothing, of the genitalia of another person who has not attained the age of 16 years with an intent to abuse, humiliate, harass, degrade, or arouse or gratify the sexual desire of any person.” (U.S. Code: Title 18, Part I, Chapter 109A, Section 2246) (Publication 114-38)

Contact between the penis and the vulva or the penis and the anus involving penetration, however slight; contact between the mouth and the penis, vulva, or anus; or penetration of the anal or genital opening of another person by a hand, finger, or other object. (SART Toolkit)