Take over from Heather

You let her push your finger into her tight, wet snatch. She's really wet, and your fingers go in easy. Heather shudders as she uses your fingers for her pleasure. After a few strokes and a loud moan from her, Heather shifts your fingers to rub on her clit. You decide to take over and rub her slippery nubbin yourself. Heather closes her eyes. After a minute of rubbing and moaning, she reaches across your body to grab your other hand. She pulls it and places it on her tit.

You get the idea, turn slightly to get in a more comfortable position, and proceed to rub her clit and fondle her breast. Your girlfriend's little sister grins as she lays back and enjoys your attention. You realize that she's gotten you to actively participate in cheating on Ashley.

You have a gorgeous horny girl putting your hands in her snatch and on her boob. You can't stop now. You plunge your fingers into her quickly, and rub your thumb on her clit. Heather moans and her body writhes to your attention. You squeeze her breast, then pinch the nipple. She squeaks and groans in alternation.

"Oh, my God, John! You're going to make me come all over your fingers! Unh!"

You lean down and suck her nipple in your mouth, flicking your tongue wildly on it, and occasionally biting it. Heather arches her back and humps her mound up into your fingers harder as she screams. Her luscious body jerks into a hard orgasm, and a flush starts at her face and moves into her tits. Her slippery juices cover your hand as she comes. After a minute of gyrating, Heather slumps into the couch, puffing like the big bad wolf.

"Oh, my! Do you make Ashley come like that, too, John? No wonder she keeps you around." She reaches over and strokes the bulge in your pants. "Now, what can I do for you?"