Pout (3.5e Trait)
From D&D Wiki
You have a tendency to pout when negotiations don't go your way.
Prerequisite: Charisma 14 or higher
Benefit: see special
Drawback: see special
Special: If a diplomacy check fails, the DM rolls d% to dictate behavior — 01-20: causes a slight adorable lip push and adds +5 to diplomacy; 21-40: causes sighing and general disinterest in further negotiation a -5 to diplomacy; 41-00: causes a full blown fit, including but not limited to threats, stomping out of the room, shouting and possibly drawing a weapon -10 diplomacy (and possible fight/arrest).
Roleplaying Ideas: Charismatic emissary, bard, someone who is used to getting by on beauty, nobility of any kind.