A person who has sexual contact with another not his spouse, or causes such other to have sexual contact with him, is guilty of sexual assault, a misdemeanor, if:

  (1) he knows that the contact is offensive to the other person;  or

  (2) he knows that the other person suffers from a mental disease or defect which renders him or her incapable of appraising the nature of his or her conduct;  or

  (3) he knows that the other person is unaware that a sexual act is being committed;  or

  (4) the other person is less than 10 years old;  or

  (5) he has substantially impaired the other person's power to appraise or control his or her conduct, by administering or employing without the other's knowledge drugs, intoxicants or other means for the purpose of  preventing resistance;  or

  (6) the other person is less than [16] years old and the actor is at least [4] years older than the other person;  or

  (7) the other person is less than 21 years old and the actor is his guardian or otherwise responsible for general supervision of his welfare;  or

  (8) the other person is in custody of law or detained in a hospital or other institution and the actor has supervisory or disciplinary authority over him.

 Sexual contact is any touching of the sexual or other intimate parts of the person for the purpose of arousing or gratifying sexual desire.