In The Picture of Dorian Gray, when Lord Henry and Basil accompany Dorian to the theatre to see Sybil, what happens to make Dorian angry?
In Chapter six of The Picture of Dorian Gray, Dorian takes Basil and Lord Henry with him to the small theatre to see his betrothed Sybil act in the play Romeo and Juliet. Dorian was attracted to Sybil because of how her acting could bring words--and art--to life. He thinks it one of her best qualities.
At the theatre this night, Sybil's acting is terrible. Basil and Lord Henry can't endure anymore and walk out of the theater, leaving Dorian there alone and angry. After the play, Sybil talks with Dorian, confessing that she did, indeed, act terribly. She explains that since she fell in love with Dorian, she knows what real feelings of love are that acting seems like an empty charade. She explains that she can't bring herself to do it anymore.
Dorian, in his anger, tells her that the only he loved her was because of her abilty to bring beauty to life through acting. After delivering this crushing blow, he tells her never wants to see again and walks out. Her bad acting, due to her genuine and real love for him, is what made Dorian angry, partly because his friends walked out and partly because beauty now lay dormant in her.