(a) A person is guilty of second degree forcible sexual offense if the person engages in a sexual act with another person:
(1) By force and against the will of the other person; or
(2) Who has a mental disability or who is mentally incapacitated or physically helpless, and the person performing the act knows or should reasonably know that the other person has a mental disability or is mentally incapacitated or physically helpless.(b) Any person who commits the offense defined in this section is guilty of a Class C felony.