In response to her name, Mattie shot Nick a glare to make anyone glad looks couldn't kill. She was sitting straight as a board, and when she'd finished with her wordless "fuck you" her eyes went shifty, flitting from object to object to possible escape route to Mr. Shitdick, which was her new name for Nick. 

And of course, when Mr. Double-Fudge Oreo Filled With Lice (known reluctantly as Jacob) reentered the room, she went a few shades paler and growled softly. Apart from that, she was remarkably self-restrained. When he addressed her she hissed loudly, but still she was speechless. Waiting. She listened sullenly but attentively to the entire shpeel with the obsidian shard. The poisoned obsidian shard that she herself should have landed on, if Double-Fudge was correct. 

"Mattie's––not looking like she's going to be willing to help us," he finished with a glance at her. She returned his glance with a venomous stare and a proud middle finger. 

"The hell I'm fucking not," she finally said, speaking over whatever Nick had muttered. "I'm more likely to chop off your wings and your balls––if you [i]have any[/i]––and sew your balls where your wings were, and your wings where your balls were." She hadn't intended the outburst, but boy, did she hate being talked about in the third person.