It wasn't really noise they had to worry about making in Avengers Tower, but there was the constant threat of being interrupted by any number of people, from the Avengers themselves to a small army of S.H.I.E.L.D. agents to interdimensional travelers aiming to take over this universe starting in Cassie's bedroom.
So it was lucky, really, that their interruption was just a sharp rap on the door frame, and Tony warning, "Put your clothes on," bare seconds before he pushed the door open. He had wafted in only a few steps when he sensed all was not as it should be, and his gaze lifted from the pile of notes from Pepper in his arm to take in the scene.
"Oh look, the proles are amongst us," he observed dryly, otherwise unmoved, brow raised cynically at the interloper. There were very few teenaged boys that should have been in Cassie's room. Parker was distinctly not on that list. Tony would prefer it if he kept himself and his hands 92 floors below Cassie's room, and maybe another six feet if he didn't start making his apologies.