He certainly gives it a try

Matt rolled over on top of his siser, his groin against hers, his clothed chest pressing her naked breasts.

"There is an expression about kissing your sister," he whispered.

"Well if there's an expression, maybe you should try it."

He didn't think that was what the expression was supposed to be saying but he wasn't going to argue with Karen. He brought his lips to hers.

Her lips felt good. Well, all the kisses he'd experienced had felt good but every girl seemed different. Karen's lips felt fuller than {if cindidate=true}Cindi's {elseif wendydate=true}Wendy's{elseif pamdate=true}Pam's {else}his old Aaron Burr semi-girlfriend's, and softer, too.{endif}

He supported his weight on his arms but pressed his hips hard against her groin. Even through his jeans, he felt the heat of her pussy and felt the silky smoothness of her panties against the roughness of his denims.

She broke off the kiss after a minute or so and smiled at him. "Hump me, Matt. Hump me for all you're worth."

He did.

Even through her panties, he felt the crease of her pussy and slid the ridge of his dick into that waiting slot.

He shifted his weight to his elbows to free his hands to grasp her breasts. Damn, he wanted to squeeze the crap out of them, mold them in his hands but he remembered her careful instruction and caressed them, building from gentle feather-touches to more aggressive moves.

She moaned beneath him. "Oh, damn. Tell me about fucking Ms. Chadra."

"Huh?"

"You want to do it, right. You want to fuck her huge tits, squeeze your dick between them and have her rub them down your length until you squirt your white cum all over her brown face. That's what you want, isn't it?"

"Uh, yeah."

"Well, tell me about it, moron."

He invented a story about unwrapping Ms. Chadra's sari, about slowly unfastening the buttons of her top, about the weight of her tits, how they couldn't be held by her bra alone and exploded out in the classroom. How he bent her over her desk and fucked her and then pulled out, flipped her over, had him eat his ass while he fucked her tits.

Karen gave him little moans of encouragement with each story embellishment. A flush spread from her face down her neck and to her breasts. She was breathing hard now, and beads of sweat trembled on her breasts, then collected and ran to form a little rivulet down her cleavage.

"Oh, yeah. Fuck me harder."

He wanted nothing more than to pull out his dick, yank aside the thin material of her panties, and plunge deep inside her. But that would be, no pun intended, a dick move and he wasn't about to risk impregnating his sister, not to mention he was pretty sure if he tried, he'd never get close to her again. Hell, this felt good enough. In fact it felt great.

And then it felt too good.

"I'm... I'm coming."

"Keep moving, you bastard. Rub me harder."

He squirted cum all over his boxers, felt the wetness of it spreading, lubricating his dick the way a pussy should, but he didn't lose his hardness. He kept pumping, kept pushing against the folds of her pussy until Karen too collapsed into orgasm.

"Oh, shit. Oh, shit. Give it to me. Give it... ah." She clawed at his back, tearing at the fabric of his t-shirt while he bent down and took one of her breasts in his mouth, sucking at it, resisting the urge to bite down and feeling her trembles as her orgasm mounted, then gradually subsided.

"That," she said, "was some good practice."