Al followed her line of sight, noticing that Snape was doing quite well too: he seemed relaxed and he was conversing with people. With Sirius.
Al smiled. He hoped Snape was enjoying the conversation and the company.
"Yes, one butterbeer, berightback," he mumbled at Aunt Hermione as he stumbled into the merry crowd, and emerged quite awhile later but with the correct drink in hand and with a heroic grin on his face.
His own steaming teacup contained precisely zero spoonfuls of sugar and a splash of milk. He toasted Hermione with it.