Mistress

mis·tress [ místrəss ] (pluralmis·tress·es) noun  Definition: extramarital lover of man: a woman with whom a man has a usually long-term extramarital sexual relationship, often one in which he provides financial support

mythomania myth·o·ma·ni·a [ mìthō máynee ə ] noun  Definition:   very strong tendency to lie: a very strong tendency to tell lies or exaggerate, which may be a symptom of a disorder myth·o·ma·ni·ac noun