It's already spreading

I was jogging with by best friend Jaden through the campus park when these two girls approached us. Definitely friends, definitely sexy, one blonde, one brunette, nice athletic body, and a juicy ass. As I am definitely the athletic guy, I like my girls sporty and freaky, and the way those two smiled at me immediately got my attention.

"May I as you something?" the brown-haired one opened. I was sweating, panting, but did my best to be as handsome as I could. Jaden knew me long enough to let me do the talking, girls just love the tall, muscular me smiling down at them. And usually he gets his fair share of pussy along the way.
"You can ask me anything." I responded with a warm, inviting smirk. Yes, that's pretty straight forward, but I've seen it so many times already: girl coming to me practically drooling at my sight, and then she asks for my number or something. Some boys dream of exactly that, but honestly: it gets annoying after some time, especially with the creepy girls. But these two were definitely hot, and I wouldn't mind to share numbers and maybe give them a good time later.
"Is it big banana time?" she continued.

"W-what?" I stammered instinctively, however before I could reassemble my thoughts a sudden rush of blood caused me to almost blacken out. For some reason my dick got hard at an alarming rate, and with my pulse already pretty busy from the running on top, it took me considerable focus to stand up straight till my dick finally also did the same. Girls always ask me if I am from Sweden, because the see a tall, blond guy and somehow assume so. But in reality I just won the lottery when it came to genes. I got the best of my parents, the looks from my mom, and the dick from my dad. And now there I was, with my full 9 inches throbbing in my jogging pants. I do wear wide ones, as at my size hiding my cock is difficult, but at full mast no pants can contain that monster. So a good part was now tucked beneath my shirt, and the bulge unmistakably. Both girls did what girls usually do in such situation and stared at my immense boner.
"So it's true..." the blonde whispered, then both giggled. But before I could focus enough again to say something, they already run of.

"Hey! You can't leave us like this!" Jaden yelled at them, and only now I noticed that he had a similar problem, however at about half the size. "Damn..." he mumbled. His Indian accent gave away his heritage, if the looks weren't making it obviously already: black full hair, beard, brown skin, and a much less noticeable throbbing 5 inches in his pants. His eyes went down to my bulge, and he raised an eyebrow. "I heard rumors, but now I know..." he reacted unexpectedly calm to our situation. But then while some part told me standing with a boner in the middle of the campus park should be alarming, I also felt pretty calm. Because they made it happen, so it wasn't our fault, so it was ok.
"What the fuck just happened?" I finally found my speech back and adjusted my cock. I am not sure when I had been this hard before.
"It's this new party app." Jaden explained "Someone made a rule that if a guy hears big banana time, you get a boner."
Something about this... no, it made perfect sense.
"So... how long is this gonna last?" I hinted at the uncomfortably erect bulge.
"Oh..." Jaden was unbroly fascinated by my massive size. "It lasts till someone else gets you off. And don't even try to do it yourself, you just won't be able to cum."
"What?!" I exclaimed "You mean I am stuck like this now till someone blows me??"
"It's not like you have a problem with that." he said annoyed "I might be stuck like this now for a while."

Since there was nothing else we could do, we eventually decided to just go on with our jogging, although it felt... different to do it with a rock-hard dick. People stared at us naturally, but it was perfectly ok if this happened because someone used the trigger on us, so we just continued. And according to the looks of some girls, I was definitely enlarging my potential to-fuck list with every step. Jaden was right about it, I wouldn't have a problem getting this down, probably could even get it done before next class if I really wanted to. But he might have some issues getting someone so spontaneously. I decided I probably might ask Cathy to give him a hand-job, she owes me a favor anyways. Nothing I can't pay back with a bit of fucking her brains out later. I smirked. It felt awkward, but strangely liberating to just have my dick up. Always such a problem at my size if I get tempted too much, and immediately I have to go through my mental routine to make sure nothing awakens down there. And now I am just running around with my heavy monster bouncing wildly with each step. Which is perfectly ok, since it happened because of that trigger.