(a) Except as constitutionally required, and then only in the manner provided in (b), below, evidence of prior consensual sexual activity between the victim and any person other than the defendant shall not be admitted into evidence in any prosecution or in any pretrial discovery proceeding undertaken in anticipation of a prosecution under the laws of this state.
(b) Upon motion by the defense filed in accordance with the then applicable Rules of Court, the defense shall be given an opportunity to demonstrate, during a hearing in chambers, in the manner provided for in Rule 104:
(1) Evidence Sought During Pretrial Discovery Stage: that there is a reasonable possibility that the information sought in a pretrial discovery proceeding which would otherwise be excluded under su