Regulus didn't wince when she stomped on his foot. That would be letting her win. He merely ground his teeth and smiled. "Honest mistake," he agreed as amicably as he could manage.
"You do, and you're lucky I got here," he said looking around real quick. He turned them so that she was facing the other group of purebloods there. He leaned in so he could whisper in her ear.
"You see the large dolt standing next to Malfoy," he asked, "He was making a move to come 'save' you as well." When she stomped on his foot again, he closed his eyes and braced himself. "You keep doing that and I'll let him," he hissed.