This is being done as a comfort for Dean. A submissive who doesn't feel safe is a submissive being misused. But this is also for Natasha. She wants obedience when there is the option of rebellion. She wants Dean to choose to submit, not be forced into it.

His response to her earns him a dry kiss on the back of his neck, her teeth nipping at the beads still wrapped tightly around his skin. The knife gets closed with a flourish and tucked into her boot, and her hands snake around to his front and the fly of his jeans. She's not teasing him, there's hardly any contact. There is purpose to her movements. She wants him exposed for the crowd that's still growing.