"Dorian, this is horrible! Something has changed you completely. You look exactly the same wonderful boy who, day after day, used to come down to my studio to sit for his picture. But you were simple, natural, and affectionate then. You were the most unspoiled creature in the whole world. Now, I don’t know what has come over you. You talk as if you had no heart, no pity in you. It is all Harry’s influence. I see that."
The lad flushed up and, going to the window, looked out for a few moments on the green, flickering, sun-lashed garden. "I owe a great deal to Harry, Basil," he said at last, "more than I owe to you. You only taught me to be vain."
"Well, I am punished for that, Dorian – or shall be some day."
– Oscar Wilde
The Picture of Dorian Gray, Chapter 9. Basil notices that Dorian has changed from the simple and unspoiled young man who used to come to sit in his studio for his picture. He blames Dorian’s transition to someone who speaks without heart or pity on the bad influence of Lord Henry. Dorian replies that Basil has taught him to be vain. To which Basil ominously says that he will be punished for that some day. This foreshadows that Dorian will later kill his friend when a horrified Basil sees in the portrait the depravity of soul that has overtaken the once innocent and beautiful Dorian.