When Sirius saw the way Harry was looking at him, he thought Harry had been mistreated at school.
He hurriedly barked, "Woof, woof, woof!" at Douglas.
Harry immediately came back to his senses. With no time to think about anything else, he said anxiously:
"Cousin... Professor, sorry, I forgot in my panic..."
While they were at home, Douglas had told Harry to keep calling him Professor once they reached Hogwarts. At the time, Harry had thought Douglas could not possibly stay on for another year, so he had not taken it to heart. Only now did he suddenly remember.
After apologizing, he hurriedly said:
"George and Fred sold fake answers for Defense Against Dark Magic, and the students they cheated have surrounded them.
Professor McGonagall was furious when she found out. She sent me to ask you to come over..."
Douglas abruptly stopped walking. Hearing that Professor McGonagall was there, he suddenly did not particularly want to go...
He quietly asked:
"Who else is there besides Professor McGonagall?"
Harry froze for a moment, then hurriedly said:
"The good students from the houses and all four Heads of House are there, but their expressions are strange. Professor McGonagall was furious at first, but then she said something to the other Heads of House, and they all started laughing.
But... but George and Fred didn't sell any answers to Slytherin. I don't know what Snape is doing there."
Douglas rubbed his head, then gave Harry a pat on the head and said disapprovingly:
"Call him Professor Snape next time. However much you dislike him, he's still your Potions professor..."
Harry gave an aggrieved "Oh," acknowledging the correction.
Sirius, however, disagreed and barked at Douglas from beside them.
Harry found it strange. Wasn't Padfoot Douglas's pet? Why did he always take Harry's side?