Manon by Jules Massenet.

Manon, a young girl being sent to a convent, arrives at an inn in Amiens, to be met by her cousin, Lescaut. She is in a flurry at her first journey away from home and her first taste of the wider world.  Left alone for a moment, Manon is accosted by an ageing rake, Guillot, who tries to seduce her. Lescaut returns and foils this plan, but leaves Manon again. A young chevalier, des Grieux, sees Manon and falls instantly in love. She is charmed and agrees to leave with him for Paris.
Des Grieux hopes to get his father’s permission to marry Manon, and protests his honourable intentions to Lescaut, who has come to Paris ostensibly to retrieve Manon from her fallen state. In reality, Lescaut tempts Manon with the prospect of a liaison with a wealthy nobleman, de Brétigny, telling her that des Grieux’s father will never consent to their marriage and has planned, in fact, to kidnap his son and bring him home, which he does.
Manon takes up with de Brétigny, enjoying a lavish life with him in Paris. She then learns that des Grieux has become a priest and goes to see if he still loves her, regretting her previous betrayal. He is firm in his resolve to lead a new life, despite lingering memories of Manon, but she is able to rekindle their passion.
Des Grieux and Manon are together again. Des Grieux accepts a wager with Guillot to try and win the wealth Manon desires. Guillot accuses him of cheating and has him and Manon arrested. Des Grieux’s father pledges to intercede for his son, but will do nothing to save Manon.
Des Grieux and Lescaut, who now regrets his treatment of Manon, plan to free her as she is marched towards Le Havre to be deported with other female prisoners. The guard is too strong, but Lescaut bribes the sergeant to allow Manon and des Grieux some time together. Sick and exhausted, Manon recalls their past happiness, which des Grieux insists they can find again. It is too late, however, and Manon dies in his arms.