Severus blushed at Lily's words again, and again he made a mental note to learn how to hide his feelings better. Feelings were things that would get him hurt, make him vulnerable, he could not afford being vulnerable.
He got out his own History of Magic homework and nodded. "That is a good idea." He agreed, hiding his feelings could wait until tomorrow though. Today he tried to enjoy the time he had with Lily, realizing that with things the way they were this might be the last time they'd study together.
"It isn't hard, professor Binns is just so boring." The moment the words were out his mouth he gasped in shock, he could not believe he had just said that. "I mean..." He trailed off, he could not lie to Lily, he really thought Binns was boring.