What makes Huck feel bad about his part in deceiving Aunt Sally?

Aunt Sally is worried about Sid's whereabouts. Huck tells her the same tale he told Uncle Silas, but it does not set her mind at ease. During the night, Huck sneaks out several times and each time sees her sitting with a lit candle on the front porch, waiting for Sid's return. Huck feels very sorry for her and wishes he could tell her everything.