Tony watches the magic trick with a little smirk on his face and a polite curiosity. Actually, he feels a bit more than polite curiosity--he's intrigued--but he's trying to play it cool.
"...Okay." Tony picks the orange in John's right hand by pointing to it with his index finger. "...I have a feeling that this is going to be one hell of a trick." He's into it. Following along carefully.