That's all Robert can ask for, and the human dares to turn his head then - unfortunately post-smile-squash - to look at him almost timidly.

"... Th-thank you..."

He wants to restate how important it is that Don be comfortable - that nothing happens that the Turtle doesn't want - that Robert understands the risks and that his body isn't so weak as it was even six months ago - but he doesn't say those things. Instead he lets his expression say them, as much as it ever does.