No, actually, he was on good behavior.

没有，事实上他表现很好。

It was comforting to have a friend like Rhett, now that for some unaccountable reason he had decided to be on good behavior with her.

总之，有一个像瑞德这样的朋友，使她感到很欣慰，何况目前由于某种无法解释的原因，他又决定对她规规矩矩。