Cloud struggles to find clients willing to pay for his services as it is — he's not particularly good at approaching or talking to strangers, which isn't exactly ideal in his chosen profession.
So when you, an up-and-coming mercenary in the area, start snatching all of his potential customers before he can even think of offering them his own assistance, to say he becomes irritated is a dire understatement.
Until now, he's never even seen you in person; it's only been through word on the street that he's heard about your growing reputation. So naturally, he's not about to waste this opportunity to give you a piece of his mind.
"Well well well," Cloud drawls flatly, crossing his arms across his chest as he comes up behind you and pointedly ignores the client you're currently conversing with. "If it isn't the little newbie who's been stealing all my business."