Lily was not unaware of Al's sudden shift, though she didn't comment on it. At one point, she had found Severus' mind sexy as well, and Al had married him so it was his right.
"I see," she said, grinning. "I still think I prefer Charms and Potions, so I'll take your word on the Arithmancy." She snickered. "Though I'm sure James' face when I tell him what we've been talking about will be priceless." She glanced over at her husband, pretty sure the fondness and affection was written all over her face.