Walking in Harry saw Severus hiding by the wall keeping an eye on everyone and moved over to join him. "Hullo Severus." He greeted him warmly before casting a privacy charm around them, more out of habit than anything else.
"Faustus was complaining about not knowing what's going on." Harry told him, "Even tried to get the information out of me after finding out I would be here." Not that he was trying to get Faustus in trouble but he thought Severus should know his son was attempting to be sneaky and get information from other avenues. Severus would likely be proud of him for it.