His head snapped to the side with the slap, and there was a snarl as he turned back slowly to look at her. "I'm not an idiot, Laura. I can read a newspaper. And I'm not going to have any part in that."

This would be around the time he pushed her back and away from him, moving away so that he wasn't backed against the wall, relaxing his pose.

He may have been away from Peter for three years while in college, but the three before that had been spent preparing Derek for the world and how to fight.

"I've always been there for you. You are my sister, and I love you, but this isn't you, Laura, and I'm not going to let you ruin what's left of this family."