He did not show that the words stung like daggers when James mention his son, because he knew they'll never get along, as much as he wanted them to. He'd pretended all his life, however, and could pretend a bit more for James' sake.
"People like your father," he said instead. "Or don't you have respect for him either?"
He wondered why Pettigrew was still standing behind him, rather than just leaving, but as he cast a quick glance behind him he realised he was completely blocking the man. Moving was a risk, James might try to get to him, but since he could not get James to move he would have to give Pettigrew the chance to. He stepped forwards, leaving the slightest gap possible for Pettigrew to move, so that the opening to James wouldn't be too big, hoping he would not jump the other man if he slipped by.
"Hell talk to the Malfoys and have him kicked out if you wish. They'd do it if you asked, at least Scorpius would."