Weasley’s face turned a tomato shade of red when he had realized their situation; Potter seemed simply exasperated.  He did kindly dispel any outburst Weasley might have had with a small look and a shake of his head.  Beyond a grimaced smile and a head nod, Potter made no acknowledgement of Draco. That was just fine with him.  Weasley elected to ignore his as well as the other Slytherins’ existence.  That was also just fine with him.