Even bigger??

Sherrie started at the blatant display of her son's enormous cock still in post-orgasmic bliss and couldn't help but to smile. His immediate demand for free wishes was daunting, but then he did satisfy her well, so maybe a little gratitude was ok.
"What do you have in mind?" she wondered while her eyes were almost locked on that sizable shaft reaching beyond his belly-button while in it's final freedom it was still growing fully hard. Before she got any answer she felt his hands back on her breasts again, and damn it was that feeling good!.
"Could you make my dick bigger?" he said as innocently as possible, yet still it ripped her slightly out of her orgasmic daze.
"What do you mean even bigger? That thing is huge already!" she laughed. This had to be a joke, right? But he kept staring at her with sincerity, and a very perverted horny grin.
"I love for things to be bigger." Max oozed sex and took another dive into her cleavage, which temporarily caused Sherrie to lose focus as she moaned.
"W-what size are you thinking about?" she wondered. Maybe if it wasn't too insane she might be willing to grant it, if it meant more of this dedication of her son to her good parts.
"Like... twice as big?" Max negotiated. This however only earned him a stared from his mom in both confusion and concern.

"Such a size would be insane!" she tried to explain to him "Your body wouldn't even be able to support a monster like that. If you calculate the blood needed to sustain an erection with that by the formula of..." But Max interrupted her physics lecture with the biggest pleading eyes he could muster.
"But mom... that's like my biggest kink. I love such things to be freakishly big!" he insisted. Sherrie stared at him trying to figure out if he was truly serious about this, because such a size would certainly be neither practical nor even functional. She tried to imagine what twice that big would even mean: his dick would probably reach up to his collarbone, and be as thick as his arm. There was no way his body could support that amount of blood needed to maintain an erection, so he'd either have to be stuck limp or erect, and according to his behavior he'd prefer the latter. He'd be a total freak with a constant boner impossible to hide, unable to have sex... and he'd probably love every second of it. Her thoughts were suddenly interrupted though as Max uttered a "Thank you, mom!!" And when she looked back at him she saw a dick on him exactly as she had just imagined it.

"Oh that fucking ring..." she cursed. It had transformed her pondering right into reality. Max now stood there with his dick the size of his entire arm, reaching from his crotch to his shoulders, and he'd have no trouble giving himself a blow-job with that thing, if he could somehow take the fist-sized tip into his mouth.
"Can I keep it, please? Mom? Please?!" he begged her, and despite her better judgement she let her feelings take over.
"Fine... for now." she rolled her eyes "But if it causes problems I turn it back right away!"
"It won't!" he cheered, and as he moved the pole of flesh in front of him wiggled alarmingly. "I think it's the perfect size, actually..." he said, and suddenly Sherrie felt how her full and oversized tits got wrapped around the shaft she had just enlarged, at least as much as her milk-filled firmness allowed. Lost in the heat Max started slowly pumping his shaft with her knockers, squeezing them good enough to make her feel aroused once again, while milk sprinkled out of her from her nipples. Yet despite him burying that shaft between her tits, there was still enough cock left for a good portion of it to show above her cleavage. There was no doubt left that he'd cum soon, all that remained was the question of whether she should let him spray that load right into her face or not. He certainly looked like he didn't care where it was going, as long as he could empty those now tiny looking balled beneath his gigantic shaft. And in that moment Sherrie realized that he in fact did love having bigger things, and was fully prepared to carry the burden of the downsides that came with them. Which immediately made her wonder if she was ready to carry the burden of those gigantic milk-bags as well...