You should promptly consult with an employment attorney. Based on what you've said you may be able to state a claim for sexual harassment. However, in many cases it is necessary for an employee to report the conduct in question and allow the employer to correct the matter before taking an action. In this case you first want an employment attorney who can counsel you as to how to file such a complaint and how to deal with the harasser if he continues to do so.
This does not constitute legal services or legal advice. Contact an attorney directly if you believe that you need assistance.
Sexual Harassment is unwelcome, offensive conduct whether it is in a physical or verbal form. The description you have given fits into the definition. The comments and overtures are creating a hostile working environment. First, you must let him know that you find his actions offensive and do not like him grabbing your body parts. It is demeaning and offensive. If you fail to say anything at all, he and those who observe these overtures may well construe it as something that is not offensive to you. Depending on the number of employees he has you can file a complaint with the Washington State Human Rights Commission or the Equal Employment Opportunity Commission. Keep a diary away from the workplace showing the time of day, the comment/act and whether there were witnesses to the event and did you report the incident to? Contact an attorney.
This answer is predicated on the facts provided in which the lawyer cannot confirm or verify. I do not represent you as we do not have an attorney-client relationship until a fee agreement is signed by you and me.
Sexual harassment is a form of hostile work environment harassment. It can come in many forms, including unwanted sexual advances and inappropriate touching. To be actionable, it must be sufficiently severe or pervasive to alter the terms and conditions of the working environment. This type of behavior does seem actionable. However, there are many defenses to such cases, including arguing that the harassment is comprised of only isolated incidents. I would recommend meeting with an attorney to better evaluate this case.