#paramour

• Lover — A man engaged in an amorous, intimate, and emotional relationship with a person outside the legal or official framework of marriage; a lover or clandestine romantic partner. In an old literary or poetic sense, the term describes a man deeply in love, a devoted admirer, or a passionate suitor, without necessarily implying a secret or extramarital character.
• Mistress — A woman engaged in an amorous, intimate, and emotional relationship with a person outside the official or legal framework of marriage; a clandestine girlfriend. In history, the term often referred to women with influential social status (such as royal mistresses) who held an unofficially recognized position at court.