Itachi could only stare at the man, though Tenten's action derailed him off his intended reaction for a moment as he made a startled noise at the sensation of nails so abruptly. Once the shock of the sensation passed though, he shifted on his feet and turned, swatting Obito hard with the back of his hand across his upper arm.

"Obito-nii-sama!" Aghast was not the tone he'd been hoping for there, and he tried to put more directness into it. "You do -not- say things like that!" He knew he was a little pink in the face, but he gave the man a stern look all the same. "No sparks. Bad Obito."