Heardtrionic Personality Disorder
A personality disorder which prevents the person from ever telling the truth, and risks them bursting into flames if they do, even in simple question situations, such as the character in Liar Liar, starring Jim Carrey.
She has Heardtrionic Personality Disorder and will spontaneously combust if she tells the truth, so please steer clear of her, just in case she accidentally answers a question truthfully.