Sophia doesn't want to stop.

Sophia smiles at Diana, but before Diana can ask you to stop, she also raises her hand: "Diana, is it ok if I keep going? I want to see what happens."

Diana shrugs, "Sure, why not?"

Sophia looks at you, and then down to your cock, which you'd slowed down in your ministrations. "Keep going," she says. She slowly pulls the down the left shoulder of her flannel, revealing her shoulder, her collarbone, and then the top of her left breast.

You start touching yourself again, tugging on your cock as you hope to see her nipple.

She smiles excitedly as you speed up, and then pulls her right shoulder bare, again, dropping her shirt just enough that you can see the top of both her breasts. She suddenly looks nervous again, glancing around as she realizes that the other girls in the class are watching her strip for you.

"I want to see your breasts," you say, "If you really want to see me hard, you should take off your shirt."

Diana interjects, exasperated. "Joe, you're already completely hard. You're not showing her anything new."

"No, I want to see," Sophia says, then shyly continues, looking into your eyes, "Will you come closer though? I don't want them to see."

You come closer, standing just a foot from her, still pumping slowly away on your cock, which is right at the level of her face. Eyes still moving between your face and your cock, she slowly reveals one perfect breast, tiny but with a perfect curve, and perfect, pink nipple.

You moan at the sight and start pumping more vigorously. She stares enraptured at you, and her fingers begin to play at her exposed nipple, shirt falling away now, modesty nearly forgotten.

"For Pete's sake," Diana says, frustrated "We're getting way off track, now. Sophia, are you done?"