You start stroking while she watches. She smiles as you struggle to hold back the sperm that are gathering in your straining cock...
She smiles and says:
"That's good, but I want to see more pre-cum! Can you make the pre-cum drip from your cock all the time while you stroke it?"
You don't think you can take any more, but the way she is commanding you is a fantasy come true. You try very hard to obey her, even though the more you try, the more difficult it becomes to hold back!