X does not laugh, but something in her face brightens -- just a little.

And a few moments later she flicks a quick sideways look at Trowa.

It's a questioning sort of look.

Is this particular lion inclined to bite her hand off?

(Not that this really matters to X, but it would likely be unpleasant for some people, and explaining why she's missing a limb would be -- problematic. For Trowa. As regeneration on that scale is not a fast-paced process. Comparatively.)