Severus looked amused. "She does do jealousy well though. It was quite amusing to watch." He paused and thought through what he'd seen in Harry's memories for a moment. He suspected Harry wasn't quite as disinterested as he made out though why the boy insisted on isolating himself was beyond him. Still that was privileged information and he would not reveal even to Draco.
"They will suspect that there is friendship at the very least," he said dryly. "After all, casual acquaintances rarely trust the other with the care of their son. That sort of thing tends to imply some sort of friendship." He leaned into the kiss then arched an eyebrow. "I will worry until they are dead and we are safe."
He started walking towards the door then shot an amused look at Draco. "I presume your son is as blond as the rest of you? Faustus and I must stand out among you like jackdaws among the doves."