Al hadn't planned to go to the memorial. Not because he disliked Cassandra, she had seemed nice enough and it was a shame that she had died. Still, the whole castle would be there and Al found his tolerance for groups was getting smaller and smaller. If not for Scorpius and the Potter lunches Al could easily have gone days without seeing a single other person. Being Jamie had only heightened his anti-social tendencies, if that was even possible. Those ten days of being bold and charismatic had left him feeling painfully inadequate, and he especially didn't want to make his brother feel the need to stick up for him more than he already did. But Lily had wanted to see him, and he couldn't exactly say no to her.
He waited while people paid their respects, hovering quietly in the back trying the best he could to not attract attention. He would let Lily take as much time as she needed, and then intercept her on her way out of the cemetery.