A. Sexual intercourse within its ordinary meaning, occurring upon any penetration, however slight; and

B. Also means any penetration of the vagina or anus however slight, by an object, when committed on one person by another, whether such persons are of the same or opposite sex, except when such penetration is accomplished for medically recognized treatment or diagnostic purposes; and

C. Also means any act of sexual contact between persons involving the sex organs of one person and the mouth or anus of another whether such persons are of the same or opposite sex; and

D. Also means masturbation, manual or instrumental, of one person by another.