Jen and Alice plopped down at the table, stroking their ponderous stomachs in anticipation of the feast served from their mother's magical rectum. They looked up as she entered the room with a trumpet of flatulence. Sweat glistened off her sagging gut as she leaned into the table and scratching her ass through her thin-stretched panties.
"Now girls," their mother said through a belch, "I'm sure you both are famished, but I think you're going to need to work for your food this morning."
Jen and Alice looked at each other with confusion and concern. Why would her mother advocate them working for anything?
Their mother saw their expressions and chuckled. "Now though I know how much you enjoy eating and am pleased with your progress, we need to address...other forms of pleasure." The girls leaned in intrigued. "Even though dating is the least of our priorities, it's important to indulge in sexual stimulation throughout each day. How often do you masturbate?"
"Four or five times a day," said Jen. Alice nodded in tandem.
"Oh, well you need to at least double that. And get each other off as well. Also, I didn't want to give you too much responsibility earlier, but from now on you'll need to pleasure me as well. Being your main provider, it's only fair." The girls considered this, then nodded in agreement. Jen rubbed herself vigorously in anticipation. She had been waiting for this moment for weeks now.
"Excellent," said their mother, pulling down her blackened briefs. "Now Jen has some experience with this, so she can give a demonstration."
Jen walked to her mother and kissed her deeply on the mouth, twisting a swollen nipple with one hand and fingering her cavernous asshole with the other. Her mother grunted with approval as they descended to the floor, landing with synchronized farts. With great effort, Jen lifted up the apron of fat over her mother's crotch, and then buried her head in her vagina, teasing her clitoris with her tongue. As her mother lied down her side, Alice approached with curiosity, then knelt down and bean rubbing her hands all over her vast expanse of flesh. Their mother relaxed further, letting out another loud, rumbling fart. Alice stuck her face between her mother's cheeks and inhaled deeply. She couldn't imagine a more heavenly sensation. Then she began tonguing her ass while massaging the cheeks. The fat middle-aged woman began breathing heavily as she approached climax. For a moment, a small voice in her head told her this was wrong. She had been a successful lawyer, who had raised her daughter to work hard and be self-sufficient; to practice discipline and avoid instant gratification. Now here she was, a slave to the id and deep perversions she never knew she possessed. She had to overcome this somehow--but this voice was muffled once more as the girls brought her to a loud, trembling climax. Jen shimmied up to eye-level with her mother and casually fondled her impossibly huge breasts.
"How was that, Mom?"
It took her a moment to respond as she came back to reality. "Uhhhh...really good. You girls learn fast." She could still feel Alice working away from behind. What had she been thinking about before? She had to remember...
"Mom," Jen said expectantly. "Are you going to feed us now?"
Ah yes, of course. That's what she forgot. "Of course dear, as soon as your sister finishes back there." She buried a hand into her daughter's hairy vagina. "But for now let me return the favor..."