Sephiroth is not particularly talkative at the best of times, even with close and dear friends. Vincent's nearly a stranger, and opening up about concerns and fears simply wasn't going to happen.

It didn't mean the concern wasn't there. The undercurrent of dread at scales, feathers, fur between his toes, knowing if he flexed his fingers short claws would appear from hidden sheaths, it's still there, just under the surface like a river beneath ice. Acknowledging it, acknowledging it to anyone beyond only himself in solitude and privacy would mean admitting if he weren't careful he wouldn't begin to pass as human anymore. Would have to begin thinking about the thoughts his mind turned to, the still easily squashed but unfamiliar impulses he knew didn't belong, and more.

So he doesn't address what he intends to do about it at all. What he chose to do was his alone to worry about; he instead finishes his choice of bandage and reaches for his boots. They'd be uncomfortable but it was less likely altered feet would be noticed later. "Are you concerned I'll turn cannibal and begin killing the convoy's people?"