The fact that Charlie hadn't burst into laughter at her attempt to be sexy boosted Penny's confidence level. She was still nervous (and who wouldn't be?), but she was no longer shaking. Without taking the wand from his throat, she bit his neck gently and quickly. She then kissed the spot where she'd bit before continuing with the charade.
Penelope wasn't going to be able to keep this act up for long: she was already fighting the giggles. "What do you reckon your punishment should be, then?" she asked in the same low voice, nuzzling his neck.