(a) An offender commits the crime of indecent exposure in the first degree if the offender violates AS 11.41.460(a) and
(1) while committing the act constituting the offense, the offender knowingly masturbates; or
(2) the offender has been previously convicted under
(A) this section;
(B) AS 11.41.460(a); or
(C) a law or ordinance of this or another jurisdiction with elements similar to a crime listed under (A) or (B) of this paragraph.
(b) Indecent exposure in the first degree
(1) is a class C felony; or
(2) is a class B felony if the offense occurs within the observation of a person under 16 years of age.