why was Aunt Polly furious with Tom after returning from Mrs.Harper's house?

Arriving home , Tom is confronted by Aunt Polly, who has learned that Tom has lied to her about his "dream." After returning from the Harper household, she learns that Tom had returned home that Wednesday night. Ridden with guilt, Tom apologizes, but tells Polly that he had meant to give her the piece of bark. Confused, Aunt Polly asks Tom: "Did you kiss me, Tom?" Upon hearing him admit that he did so because he loved her, she forgives him and sends him off to school.