For the second time that conversation, Thor has to resist the urge to turn his head to look at his brother.

"Would you let me cut your hair?"

It's not so much about the hair (Thor wouldn't feel comfortable cutting Loki's hair -- braiding it, yes, cutting it? no), so much as it is about the question behind it: do you trust me? Thor resolves himself not to get upset at the answer; he's pretty sure he knows what it will be.