Charlie paused for another moment so he wouldn't say anything cruel. "Percy doesn't always mesh with the rest of the family. We love him, but I think he takes the way the Weasleys show affection personally. We rag on everyone. He's just the only one who doesn't see it as a joke. Ron sometimes too. Ron's a little like Percy that way, but he's gotten better over the years."
Charlie knew that everything that had passed during the time when Charlie wasn't speaking to the family made it hard to continue this kind of tough love. Everyone was afraid he'd take any joke personally.
"I just... Percy is very good at keeping his reactions and emotions inside, and the fact that he had to leave rather than pretend there was nothing unusual about you being there means he's not okay with it."