Find out what a "good girl" will do.

"So, you'll be a good girl, and do what you're told now, is that right, Meghan?" you ask her, your eyes roaming over her petite nudity.

"Yes Sir, I'll be good, I'm sorry, I won't be any trouble to you." She smiles at you tentatively, relief coming back to her face. You look at her naked body, your cock starting to stir again with desire.

"A moment ago, you said you'd do anything if I didn't take you to see Grampa," you grin. Her smile fades a little.

"Well... Yes Sir, but..." she stammers.

"If you're changing your mind, we can always go see him," you say, your voice flat. Fear floods back in her eyes.

"No sir, I didn't mean that, I don't mean that, I just, I'm just afraid..." she looks up at you, apprehensive. "I'll be good to you, Sir, please let me, Sir. You wanted me to pose for you, to show off for you. I'll do that for you, Sir, please let me do that, Sir." She smiles at you, trying to cover her nervousness with flirtation.