Of course, Remus had heard him. It was unsurprising but he was more focused on comforting Sirius for the moment, adjusting the way he held his arms to pull the younger's head down onto his shoulder. "Settle in, cuz. You're not escaping that easily," he didn't want to admit he was somewhat afraid of what Remus was about to tell him. The castle was so empty, so devoid of life. What in the Hell could have happened? So Sirius was his emotional support cousin.
And there was a lot to go over. The longer Remus went on, the more his brow furrowed and the darker his expression got. That was only six years from his time. Were they already starting to experiment? A ringing started in his ears when he started to put together everything with the mention of the deaths. For a brief second, it might have looked like he was about to allow a sudden anguish to take him over - and then it was gone. He could mourn later. Always later. He only started actually registering what he was hearing when he heard Ron's name and his brain started to catch up.
Teddy broke his own serious expression by faux-gagging at the name Lucius, almost like a cat about to cough up the nastiest hairball ever known to man. "First thing's first," he turned his gaze on Remus, "You're my dad. Wolf and all, top to bottom. The only way that would ever change is if you were an utter arse. Lucius Malfoy levels of utter arse." His knee was bouncing, the only outward sign of his anxiety at the moment. He'd gotten control of his hair again. "Secondly, what can I do to help?" This was directed at both of them, especially since Sirius knew what he could do.