Grace Winston, college student

Frank finally found the time to boot up his favorite game after all the stress of the past few days. Two exams in one week, and of course way too little time to prepare. Partly because he spent too much time gaming, but that was beyond the point. He was just about to load into his first match, when his girlfriend came in.
"Hey babe." she greeted him.
"Hey." he looked at her and could immediately tell that she was in the mood.
"What cha' doin?" she came closer and wrapped her arms around his neck, making sure her tits touched his back. He loved her tits, only B-cups, nothing to write home about, but he had a taste for them. Frank gave her a quick kiss, then returned his attention to the game. "Sooooo.... you might have not noticed, but your girl is actually a bit in a heat." she teased him with a soft voice.
"Yeah..." he mumbled, already focused on the game "Will take care of that later. Just let me get my head clear first." His eyes were fixated on the screen. Normally this would have been yet another day of countless hours of frustration till he finally got off that PC, but not today. Because one of the reasons she was horny was that new app that somehow installed itself on her phone, and that promised to be able to control anyone's dick.

Frank was glad when she let go. As much as he loved her, he just needed his time off, and she rarely accepted it just like that. She'd probably make a scene out of it later, but for now he had some peace of mind. He noticed her pulling out her phone, usually a good sign when she started complaining to her best friend. However a moment later he suddenly felt a numb feeling in his mind. Kind of like a buzzing, like getting one of these massages, but he couldn't quite pinpoint it. Everything just felt so... numb. He kept playing the game, but he felt more like a machine doing the things he was supposed to be doing. He suddenly felt his dick growing fully erect, but once again he felt barely anything with it. Like suddenly turning rock-solid was nothing out of the ordinary.
"You seem to be pretty horny as well." Grace suddenly wrapped her arms around him from behind again. Frank could feel how her hand started working his shaft through the fabric at first, and then she unbuttoned his pants.
"Yeah." he mumbled. He felt it, but he was so distant, like he was just watching someone else do it. "But later babe. I am sure I am gonna get it up for you in an hour or so again." It felt so odd to hear these words form his mouth. There were his, yet it felt like he was hearing them through a speaker from someone else. Grace let go again. He could tell she was angry. Denied two times, but he just wanted some peace of mind.
"Yeah... let's make sure of that." she said and suddenly giggled. She typed on her phone for a moment, then eventually left.

Frank suddenly felt like he woke up. Like he had been stuck in a daydream and then someone or something caused him to return to reality. He was very confused by what had just happened, but quickly blamed it on the stress. Downstairs though his dick was still throbbing, raging even. He could feel it, so hard, but he wasn't even horny really. He tried to return his attention back to the game, but even after several minutes his cock did not seem to want to go down at all, not the slightest. And eventually it demanded so much attention, that he kept loosing fight after fight.
"Fuck!" he cursed and closed the game. Two lost matches because his head was coming up with all kinds of sexual things, because somehow his dick had decided to throw a tantrum today. He probed his shaft and it was as hard as it had ever been. Unsure what else to do he tried to stuff it back into his pants as good as he could, and then went over to the living room. After all she had been asking for it, and it seemed like his dick had made the decision for him.

Frank panted. That orgasm had been good. Grace was resting next to him, panting also and shivering even. Today she had been especially wild for some reason. She rode his dick like a maniac, completely unhinged. It was a miracle that he hadn't cum earlier, but just when she came on him he was thrown over the edge. Frank looked down, removed the condom, made a knot into it and put it aside.
"Babe... my dick is still hard." he realized. Grace was snuggling on his chest, exhausted, but she looked down and grinned.
"You want another round after this?" a giggle followed her.
"Nah... I am just worried." Frank answered "I got hard for no reason earlier, and since then I feel like it is stuck that way. Kinda scared to be honest."
"There is no reason to be scared." Grace said with a sigh and reached for her phone "It's because I got selected for this app that can control anyone's dick." Frank looked how she was fumbling with the phone, but what she said made no sense.
"Babe, that's impossible." he told her "No app can do that." But she seemed to be convinced. He watched the iCock app loading, and then suddenly he felt that numb feeling again. Like the whole world had just be turned into cotton, and he felt everything so distance.

The app had a dick on the screen that strangely looked like his own, even the stats matched.
"See: I put you to 100% erect and locked it." she pointed at the screen and giggled. "It has all your stats even." It took Frank considerable effort to even speak in this state, but he didn't even feel alarmed, just very numb.
"Babe, this is not possible. A phone cannot do that." he reminded her. Suddenly a grin formed on her face. The mischievous type that should get his warning lamps glowing, but nothing. He just laid there and watched what she was doing.
"I bet you always wondered what it would be like if you were bigger, do you?" she looked into his eyes. The app had his exact 5.2 inches, and Frank didn't know what to say, so he just nodded and mumbled a "Sure." He watched how Grace moved the slider to 8 inches, and when she let go he immediately felt a strange tingle in his dick.
"Oh fuck!" she exclaimed. Both stared at his now much bigger cock. At this point Frank knew he should be in panic. Somehow his dick just got bigger, and if any of that was true, then his girlfriend had an app that could literally change his dick. But he wasn't. He was still calm and numb as before. Even when she - clearly excited - run her hands over it, he could feel the arousal, but it was more like reading it from a distant sign saying 'Frank just got hornier.'

"Mind if I try something?!" she stared at him with a hint of madness in her eyes. Whatever it was that she was trying, Frank should be saying no at this point and figure out what the hell was going on. But he couldn't. Somehow he could only nod and say.
"Go wild." And that was all she needed. He watched how she ramped up the slider to the limit, and a second later he felt that tingle again. Then his cock rapidly expanded right in front of his eyes, till the head of it, now about the size of his fist, came to a halt just below his chin.
"Holy... fuck." Grace exclaimed. She stared at him with her eyes wide open, then back at that dick. In disbelieve she had to probe his dick, and only when she had both hands around his shaft, because one no longer was enough, and that massive slab of meat bounced back on his chest with an audible smack she accepted that it was indeed real.
"So what do you say now, big boy?" she laughed, now sitting up straight to get a better view of his new member.
"It's nice." Frank admitted. That was the furthest extend of the emotional reaction he was capable of at this point.
"Your balls look tiny now." Grace giggled and touched them. "Oh... wait! There was a balls option as well!" With the same maniac expression she returned her attention to the phone briefly, and just seconds later Frank felt his balls expanding till he sported two globes the size of apples each. "Now they are matching." she said and laughed. Then madness overcame her.

Her attempt to get the head of that cock into her mouth failed dramatically. Frank wished he could do something else but to absently watch her handling his cock, but at least the kisses on that massive head felt very good. She pumped his shaft, staring at him with raw lust, and played with his balls.
"I bet you like that, big boy." she teased him, and Frank nodded with a faint smile. She sat down on his belly in reverse and squeezed the shaft between her now way too small tits. Frank instinctively reached out and kneaded her boobs, gave himself a tit-fuck with them, much to her delight. But this wasn't because he was particularly horny, more like muscle memory. Although it did feel good, he had to admit even in his state. Eventually she decided though to make him cum again, and as the current method didn't do the trick, she went back to his side, pumped his arm-sized cock with one hand, and played with his orange-sized balls with the other.
"You close?" she eventually asked.
"Yeah." Frank was very close actually "But I somehow can't cum." Grace looked at him confused for a moment, then burst out in laughter.
"Sorry, one sec..." she reached back for the phone, typed on it for a moment, then another one of those dangerous grins, and suddenly Frank felt like something in his dick unlocked. No, worse: shifted. Grace put the phone back on the nightstand, grabbed his dick ans balls again, and started pumping like before. Just this time it took mere seconds till Frank was blown over the edge and came. Way too early he figured, but his mind was occupied with cuming than to think about it. And it turned out his balls were not only visually bigger, they also produced a load that was way beyond his usual amount. Thick ropes of cum left his oversized monster-dick, splattered against the wall and onto his face and body, till the fountain eventually run dry.

"Sooo... you like that?" Grace was done cleaning him up, which had required half the pack of tissues.
"Yeah, it's nice." Frank said. This wasn't his opinion, he had no opinion, he just said what he thought she would want to hear.
"Could keep you like this for a while." she offered with a naughty smile.
"Sure, why not." he agreed. She stared at him with her eyes wide open.
"For real?" He could easily tell how much that idea turned her on.
"Yeah why not. You seem to like it." Frank said. A part of him was screaming, but that part was very, very far away. He watched her shiver in response, clearly massively turned on by the idea of her boyfriend walking around with a gigantic, rock-hard pole.
"I will definitely make that up to you..." she almost moaned, and he felt her hand gently work his still perfectly erect shaft.