Tony is the only person who Bruce passively accepts affection from, so it doesn't phase him. "I'm really not sure how this is going to go, but at least I know one way it won't go." And that is what matters. He smiles at Tony and then blinks over at Alex. "Why would you have to leave us alone? I thought you wanted to take notes." On test subjects getting sedated by the cats. What else would he be talking about?