I stared , dumbfounded, at Marnie as she dismounted, cum drooling from her just violated pussy, and walked over to my Grand-daughter, offering her a taste of my cum. I was even more shocked when Morgan dropped to her knees and started lapping up the drips of cum and cunt on Marnie's inner thighs, moaning as she did so..  Marnie turned her head and said to me, "I'm willing to honor the fact that you won't directly violate Morgan, but I can't pass up an opportunity to educate her either." 

Morgan was obviously enjoying it, her face now buried in her besties leaking snatch.After sucking and slurping on Marnie for a couple of minutes Morgan stood, faced Marnie and began kissing. Not just lip to lip, but sharing the combined nectars of Marnie's and my lust.  Much to my surprise, I was instantly hard again, but the girls didn't notice. They were too involved with each other, Morgan's hands on Marnies breasts and Marnie's hands on Morgan' butt cheeks, holding her close and grinding, mound to mound.

I just watched in awe, playing the voyeur, as the two girls loved on each other. The thought of Morgan and I coupling up was tempting for sure, but I couldn't justify it in my head. What if we got caught? My thought patterns were interrupted by my grand-daughter, who said, "Grampa, Marnie needs another lesson. Do you think you could help her out?" She winked as she and Marnie disengaged.

Instead of facing me, she presented her soft, round ass as she straddled my legs, reached between her own, and guided me effortlessly inside her. "God, Grey, you feel so good, nestled in my cunt." she sighed as she slowly sank down on my length. Knowing how excited I got listening to her talk dirty she leaned back, whispering in my ear, " Fill me again, with your hot, sticky cum." I grabbed both of her breasts, tweaking her nipples as she ground onto my cock, "I want you to empty your balls inside me,"

Truth be told, I wanted it just as much as she did. The thought of me fucking this wanton young girl, taking sloppy seconds, feeling every inch of her tight pussy with my cock, drove me to go faster and harder. As suddenly as it started, Marnie pulled off, planting herself on the floor between my legs. She stroked my hardness. "You don't mind if I show her just what a cock does when it cums, do you Grey?"

"And if I did?"  I said, knowing I was in no position to bargain.  Her hand slid off leaving me poking straight up in the air.

"Then you don't get to cum." She winked, knowing who was in control.

I was trapped, and I knew it. " It's yours to do with as you wish", I said, resigned to the fact that I had no bargaining power. Using her own pussy juices, Marnie jacked my shaft vigorously until I moaned, "I'm.. I'm cumming!" My cock errupted and warm cum slid down my shaft, over Marnies hand and onto my balls. Marnie licked up the creamy sauce, turned to Morgan. The gleam in my grand-daughters eyes indicated how willing she was to drink from me. The two girls shared another sloppy, cummy kiss as I watched in both dread and amazement.

 "Grampa, did you and Gramma have any toys you played with?" Morgan asked as she licked the last vestiges of my orgasm frm her lips.

I considered lying to her about it when Marnie started sliding her hand up and down my wilted length. "In her closet, there's a box of her stuff." I said as my conscience wavered, yet again. Morgan soon returned with the box, a look of surprise and glee all over her face. 

"What's this one?" she said holding up a purple silicone, Y-shaped object.

"That was Gramma's Rabbit."

"Rabbit? What was it for?"

"Clitoral and vaginal stimulation." I said, twisting the bottom and bringing it to life. 

Marnie interceded at this point, "The big end goes in your pussy, the little end buzzes against your button. Here, let me show you." Marnie grabbed it from my hand, pushed it deep in her cunt until the smaller arm pressed against her clit. She pulled it out and handed it to her friend. "Go ahead! Try it!"

"Oooooh my God!" Morgan crooned as it slipped easily inside her. 

I suggested that she sit down across from us and play while Marnie did her magic on my not-so-grandfatherly cock. She did, splaying her legs to give me a perfect view of her teenage cunt. Lust contorted her face as the vibe plundered her pussy. Her breath became ragged, punctuated by yips and groans as the toy propelled her toward a mind blowing orgasm. "Oh God!... Oh fuck! Fffuuuuccccckk!" she screamed letting the purple machine plop out as her hands covered her mound and she writhed on orgasmic bliss. Her chest was flushed, her nipples erect as she slowly came down "Un-fucking believable!" she panted.

Our eyes met, I smiled. " The toy box is all yours," I said, "But, you'll have to leave them here." Marnie let go of my monstrously hard cock, crossed the room and picked up the rabbit. Morgan stood, strode across the room, sat in my lap, and gave me a kiss on the cheek.

"You're the best Grampa."

The warmth and softness of the young teen on my lap made my cock twitch. The feel of her young breasts pressing against me made me want to do things. Evil things. Wrong things. Things that could destroy my family. But, God, I wanted to rearrange her in my lap and let my cock worm its way inside her, ravish her, give her more orgasms, and give me at least one. One where my throbbing member expolded deep inside her.

My perverted thought process was interrupted by Marnie.  "Move over Morg!" she said as she sat on one knee while Morgan took the other. " I know you won't fuck her. You want to, but you won't. But, wouldn't you like to taste her?" she said to me, pressing the larger end of the rabbit to my lips. I opened up taking a good size chunk of the latex toy in my mouth and sucking my grand-daughters cum off it. With her other hand she gripped my cock and started stroking it again while she kissed me, tasting her besties juices off my tongue and lips.

The rest of the afternoon was spent watching the girls play with my late wife's toys, listening to them laugh, and cum,  until it was time for them to head to their respective homes for the evening. As I got ready to head off to sleep, I contemplated my situation, wondering how much further this would go as I sucked more of Morgan's juices off the vibrator.