We should distinguish between your feelings and those of your negotiation partner.
Your own feelings: You are angry, you are disappointed and even really mad. Your negotiationpartner does not respect you in the way you want him to. You think that this is not ok and that you should not put up with everything. You are allowed to have these thoughts, but you are not allowed to express them. In addressing your own feelings you make yourself vulnerable. Your opponent will realize very quickly how you think, what is important to you and, above all, what you are afraid of. Please, stay relaxed, do not give careless answers, and keep your feelings to yourself.
The feelings of others: It is extremely dangerous to address your negotiation partner’s feelings. “That means you are disappointed …” or “You are angry …” The question is—why do you address these feelings? Do you want to show some empathy with your negotiation partner or that you understand your opponent? Don’t do it, most people are very sensitive when it comes to these tactics.
Your own and other people’s feelings: This combination is used in absolute crises, such as hostage takings. “If I understand your response correctly, you got very angry because …” This combination has a strong de-escalating effect because it does not sound condescending and gives the opponent a chance to correct it. In combining your own feelings with those of your opponent, you will be able to lead the negotiation back to the facts.