SEXUAL ABUSE SHIELD: The following evidence is not admissible in any criminal proceeding involving alleged child sexual abuse: (1) Evidence offered to prove that the alleged victim engaged in other sexual behavior; and(2) Evidence offered to prove the sexual predisposition of the alleged victim. (b) Exception.— Evidence of specific instances of sexual behavior by the alleged victim to prove that a person other than the accused was the source of semen, injury, or other physical evidence shall be admissible.