Tonight's opera is the beautiful La Traviata. Here is the first scene, in which the party goes on while Violetta stays behind due to illness, and Alfredo stays behind to confess his love.
This is a truly wonderful opera. You can read about it here. And you really ought to see a production of it someday.
The soon-to-be-happy and then-to-be-unhappy and then-to-be-ever-so-briefly-happy-again couple: