We have many specific cues that communicate disappointment to the other party. Some studies indicate we offer more concessions if we detect physical disappointment in the other party, such as through a downward look or frown.[ii]
Making oneself “small”, arms crossed, head down, legs crossed, or shoulders slumped.
Disregard this non-verbal cue and focus on the objective data. Or, communicate your own disappointment and see if they pick it up and sweeten the offer.