Lily watched him proceed ahead without her, her mouth hanging open as he grabbed another girl and promptly kissed her. She wasn't very surprised when she saw the smack coming, but walked over towards him anyway. He was acting so strangely she was nervous to see how he would take to it.
She gave the girl an apologetic look before turning her attention to her friend once more.
"Sirius, what's gotten into you?" she asked, grabbing his arm and pulling him to face her. "Are you feeling alright? I mean...this isn't like you at all! Do you need to go to the hospital wing? Or maybe I could make you a potion..." But what potion would she make? She racked her brain and couldn't come up with a logical one. She had already exhausted her help with Professor Slughorn so she would have to figure this one out on her own.