"Intersect in a point." His hands stopped at the bend of her thighs, his thumbs below, his fingers above, framing her dark brown triangle with his hands. "A vertex." He grinned, slipping his finger through the center of her, making her shiver. "This, right here… this is the vertex… do you feel that." His finger moved gently over her clit, sending an immediate rush of blood there.

"Yes," she breathed, her eyes closing for a moment.

"So the angle is this circular span between the two lines." He rubbed his hand over the futon beneath her. She propped herself on her elbows, looking down at the cushioned surface, her head cocked. "This is a 90 degree angle." He arranged her legs just so. "With a third side, this is a right triangle. An angle, if it's less than 90 degrees, is an acute angle." He slid her legs nearly closed by the ankles. "And I have to admit, this angle is pretty damned cute." He looked fondly at how her lips pressed together in a sweet little pout. She was giggling, now.

"An angle larger than 90 degrees, now… that's an obtuse angle." He pressed her legs open, out, out, wider. She gasped, wiggling, until finally she cried, "Ow, ow, ow, ok I got it, stop!"

"Good girl." He smiled. "Now…you can understand Pythagorean's theorem…"

She shook her head, already pouting. "David, no. There's no way. I try and I try, but I just don't get it." She turned onto her belly and moving to get off the futon. "I think I'm just mathematically challenged."

David watched her moodily cross the room, leaning back, a small smile playing at his lips. He started unbuckling his belt. Her head snapped toward him immediately. She heard that sound in her dreams sometimes, followed by the slow click of his zipper, the push of material, and-oh, yes, the freeing of his cock-which always made her ache with longing. She settled cross-armed against his dresser, and she knew he could see her reflected in the mirror, her bum propped on the edge. The sight of her leaning there made him visibly harder, and he reached down and tilted his cock toward her, an offering.