Grab the back of her neck and slide inside

The rush of pleasure as you see your friend looking up at you fills you with a thrill, and you run your fingers up the back of her neck to the base of her skull, guiding her head closer to your dick.

She obliges, taking you into her mouth. She sucks lightly, caressing your shaft with her tongue, and looks up at you lustfully. It's such a hot sight that you almost lose control.

"See how it's making him feel so good?" Diana asks the class. The girls nod, enraptured.

"Diana!" you moan, holding her head with both hands.

The warmth of her mouth and the softness of her lips enclose you in pleasure, and you are barely able to hold yourself back.

She starts to slide her head up and down your shaft, moistening it with her tongue.

"Diana!" you moan, as you feel your balls tightening with the impending orgasm.

"Joe, please don't climax yet," says Diana. "Girls, see what's happening to him? When his cock starts to spasm, he's about to orgasm."

Diana pulls her mouth off your dick, and continues to stroke it with one hand.