[cashflyer]

Your realtor is your agent. In most states, you even sign an agency agreement with that person. You have a right to direct and/or limit the actions of your agent. That being said, you can instruct your agent with exactly what you have said here. And you can go one step further and instruct that all showings must be approved by you. Finally, you as the seller have the ultimate authority for approval or disapproval of all offers brought to the table. You can refuse all offers made by your adversary and his associates.

However, your agent may not want to dick around with these restrictions. It is within their right to resign and tell you to find another agent.