Any person convicted of any violation of this subsection shall be punished by imprisonment in the custody of the Department of Corrections for not less than three (3) years nor more than twenty (20) years, except when the child is under twelve (12) years of age at the time the offense is committed, and in such case the person shall, upon conviction, be punished by imprisonment in the custody of the Department of Corrections for not less than twenty-five (25) years. The provisions of this subsection shall not apply unless the accused is at least three (3) years older than the victim, except when accomplished by the use of force or fear. Except as provided in Section 51.1a of this title, any person convicted of a second or subsequent violation of this subsection shall be guilty of a felony punishable as provided in this subsection and shall not be eligible for probation, suspended or deferred sentence. Except as provided in Section 51.1a of this title, any person convicted of a third or subsequent violation of this subsection shall be guilty of a felony punishable by imprisonment in the custody of the Department of Corrections for a term of life or life without parole, in the discretion of the jury, or in case the jury fails or refuses to fix punishment then the same shall be pronounced by the court. Any person convicted of a violation of this subsection after having been twice convicted of a violation of subsection A of Section 1114 of this title, Section 888 of this title, sexual abuse of a child pursuant to Section 843.5 of this title, or of any attempt to commit any of these offenses or any combination of convictions pursuant to these sections shall be punished by imprisonment in the custody of the Department of Corrections for a term of life or life without parole.
As used in this subsection, "employee of an institution of higher education" means faculty, adjunct faculty, instructors, volunteers, or an employee of a business contracting with an institution of higher education who may exercise, at any time, institutional authority over the victim. Employee of an institution of higher education shall not include an enrolled student who is not more than three (3) years of age or older than the concurrently enrolled student and who is employed or volunteering, in any capacity, for the institution of higher education.
As used in this subsection, "employee of a school system" means a teacher, principal or other duly appointed person employed by a school system or an employee of a firm contracting with a school system.
Okla. Stat. tit. 21, § 1123