Scorpius was not, in fact, busy. But he knew an out when he saw one and he wasn't about to shut the door without seeing Bellatrix out of it first. He smiled back.
"Of course," he replied, ever agreeable to a woman who went down in history as Voldemort's right-hand woman. Who wouldn't be? "Have a good day, Aunt." It would be in his best interest to stay in her good graces.