[Well, that was easier than he thought it'd be. The smirk on his face widens into a grin as he watches his double's reaction, and this time, there's definitely something akin to scorn bubbling beneath the veneer of his calm; how dare this impostor wearing his face be so pathetically obvious?

Actually, it's interesting that such a vague description is able to immediately conjure a specific person to his double's mind. "I wouldn't take anything he has to say seriously"? Oh, on the contrary, now Gary thinks that he'll have to pay extra attention to anything that comes out of his mouth.]

Well, I'm sure a lot of useless garbage comes out of his mouth - he doesn't seem to have much of a filter - but he has to say something useful once in a while, doesn't he?

[His tone is nonchalant, casual.]

That's why you bother with him, isn't it?

[And here he's bullshitting - he doesn't know what the relationship between them is like, of course. Whether or not it was one of begrudging tolerance on Gary's part. Whether or not Gary even really gave him the time of day - but he has to be inclined to think this guy has something on Gary for him to react the way that he did.]