Oliver wanted to say that Albus didn't have to apologise to Percy, until Percy apologised to Oli for not telling him. But Percy was allowed to keep things to himself, he didn't have to tell Oli everything. "It'll be fine, Al, Percy's not going to be mad." He smiled a little and added: "And if he is I'll kick his ass for you, aye?" Oliver really didn't think that Percy would get angry, since the other was so determined to get along with his family.