She gets it. He wishes she weren't hurting in the same way he is, but she understands-

There's a sharp intake of breath when she speaks - I'd do anything for you. - that leaves him reeling for a few moments. He wasn't expecting to hear anything like that from anyone, let alone to have it said so plainly, and ​he needs the time to catch his breath and try to think. Does she mean it? Can he ask?

"Can you-" He falters - she's hurt too, it's selfish to ask, but he needs to know - and tries again. "Can you promise me something?"