Sexual harassment can occur in many forms. One is unwanted physical contact. This could happen in the most seemingly innocent manner or be overt. The key to the matter is that you did not welcome the behavior and you did not invite it. If you feel that a pat on the back is offensive, then you should tell the person you do not like it and to stop. If it continues, you may have a case. Physical contact can be more than a pat on the back; it can be any type of touching, grabbing, patting, stroking, rubbing, massaging, physical assault, coerced sexual activity, or rape.
When someone is behaving towards you in an unwelcome manner, verbally or physically, you may be the victim of sexual harassment. If this person is physically touching you and you don't want it, you need to fight back.