My understanding is, As long as dual agency is disclosed, it is permitted. The fact that you seem to know of it would seem to be the disclosure proof. If you do not want it, you need to speak up. It seems you specifically disapprove of it. He can have the transaction handled on the buyer side by a colleague with no personal knowledge of your situation. Always keep in mind, the transaction is sensitive and a buyer is due respect, too. Loosing a buyer should be kept in mind as a risk. Much depends on the situation and the factors that if disclosed to the other side would be unfair and unethical. Most, not all, transactions are undramatic. But you can see, the buyer and seller posted below do not approve of it on principle. It is done properly quite often, we all acknowledge.