[ ...well, maybe Loki didn't tell Thor because he didn't want him to go with him, and didn't want to get into a fight about it? Or maybe it just didn't occur to him? They're both grown men, after all...

But Katara didn't really want to take Loki's side, or offer up arguments for him. He'd never been much more than polite to her; Thor was her friend. But she didn't think just agreeing with Thor would help him very much either. ]

Does he usually do things like this? On his own, I mean, without telling you? Or did he have a reason to not tell you this time?