[Who says it's one or the other? Clearly it's both. It's also not surprising to see Kimihiro engaging in yet another vice.]

You never are, so at least there's some consistency.

[Shrugging that off easily because he couldn't care less on the subject. He had no reason to associate with either one of these clowns, so he would prefer to keep this interaction to a minimum. Then in response to Iwa..]

Apparently, you're going to overact like a complete buffoon and remove all doubt that what I said could have been in error.

[Luckily for both of them, Kaiba really isn't interested in prolonging this]

You sure showed me. [Adding one last sarcastic dig as he took his leave.] Try to pretend you're housebroken while at the party.