Circe was trapped. Odysseus had her wrist with the dagger in it tightly held.

Odysseus: "You've lost."

Circe: My nymphs are like my daughters I protect them at all costs, the last time we let strangers through we faced a heavy loss. You've given me no reason to bestow you in my trust, but everyone's true colors are revealed in acts of lust..

Odysseus: "I'm not sure I follow...?"

Circe flirts with him, and pushes him onto the bed. She gets onto his lap, straddling him.

Odysseus was trapped.