the offender previously was convicted of or pleaded guilty to a violation of this section, rape, the former offense of felonious sexual penetration, or sexual battery, and the victim of the previous offense was less than thirteen years of age.
Evidence of specific instances of the defendant's sexual activity, opinion evidence of the defendant's sexual activity, and reputation evidence of the defendant's sexual activity shall not be admitted under this section unless it involves evidence of the origin of semen, pregnancy, or sexually transmitted disease or infection, the defendant's past sexual activity with the victim, or is admissible against the defendant under section 2945.59 of the Revised Code, and only to the extent that the court finds that the evidence is material to a fact at issue in the case and that its inflammatory or prejudicial nature does not outweigh its probative value.
R.C. § 2907.05