Got a good little story on this subject from back in my student days. I was on my way out for a drink one night with a mate and a close female friend of mine who were all part of the same social circle. The female friend was an average looking girl but with the most amazingly proud and bouncy D cup breasts you've ever seen, and she and my mate who was with us had been out at a rock club the night before and were walking about it when my mate mentioned being stood at the urinal in the toilets next to a gangly, long-haired skater kid who'd just appeared beside him. As my mate did what needed to be done, he wondered why, in his peripheral vision, the skater kid appeared to be resting his hand against the wall, because his forearm seemed to be held forward roughly horizontally at waist height. My mate must have turned his head slightly out of curiosity, and when he did so, he realised that it wasn't a forearm he'd seen in his peripheral vision; the kid had simply pulled his penis out to relieve himself.
"Fucking hell, this long-haired kid who came and stood next to me in the bogs last night had an absolutely fucking massive willy... I honestly thought he was pushing his hand against the wall with his arm out of the corner of my eye, but it was just his todger! He was packing fucking heat, man."
At this point I should mention that we'd all been friends for just over a year, and my female friend, who was 18 at the time and in a long-term relationship with her high school sweetheart, had initially been a bit infatuated with me. The upshot of that was that after confiding in me about difficulties with their relationship one night, we ended up having sex, albeit once only. At about 8"x5.75 erect I'm very well endowed by any objective standards, and she was gobsmacked when she first saw my by then semi-erect member, but was clearly in ecstasy while when I had my way with her that night and I was getting balls deep inside her by the end of our night together. She'd never had sex with anyone other than her high school sweetheart before, and their relationship didn't last long after that night, and I wondered if her experience with me and my size killed it for her with him, particularly as she said when I was flaccid after our first session that I was much longer soft that her boyfriend was with an erection. Our friendship inevitably went a bit weird for a few months afterwards but eventually got back to normally, but I wondered all the more whether I'd given her the big dick bug on that night a year earlier when I heard her reaction my friend's exclamations about the almost grotesquely well-endowed skater kid at the urinals.
"Really?! What did he look like? Was he on the dancefloor?", she asked.
"If he did he'd have been the one who looked like he had three legs", my mate replied.
"What was he wearing? Did you see him again?" she asked. I can't remember what he said in response; bar being quietly turned on by her undisguised big dick lust and half-wishing I'd seen this kid and his apparently prodigious member for myself, I didn't think much else of it.
Until about two weeks later, when we were in the same club that they'd been out to that night when my mate had seen skater boy and his equine phallus in the gent's.
About an hour after we got there, my mate put his arm around her shoulder and point toward a gangly, long-haired kid in a baggy jeans the other side of the dancefloor. I wondered what they were talking about at first amidst the poor light and the noise, as she struggled to figure out who she was pointing at. Then I saw a kid with long hair and wondered, then noticed her open mouthed and laughing. She'd had a couple of drinks by this point and within a few minutes was hovering around him. She'd chosen her outfit well, a low-cut crop top which really flattered her plump assets.
For my part, I was pretty eager to see if this kid was all he was cracked up to be, and kept half an eye on the two of them all night as they flirted, with a vague idea of following him into the gents. About two hours later, despite having only just gone for a piss a few minutes before, I found my feet carrying me back there as he made his across to that side of the room.
I went in and stood beside him. It wasn't hard to see how my mate had, in his peripheral vision, mistook this lad's member for his forearm. It really was that big. I'm probably about 6" soft when pissing, and his cock absolutely dwarfed mine. I'd never in my life seen another flaccid cock as big as mine, let alone bigger, but this kid's softie was half as long as mine again, and thicker.
I was too was slightly pissed by this stage, but not too pissed to remember that, in my partial drunkenness, I felt no shame about blurting out, "fuckin' 'ell, and I thought I had a big dick." "Haha! Cheers mate", he laughed, seemingly drunk enough himself not to be too embarrassed. "My mate out there, I shagged her last year dude, she loved my dick so Christ knows how she'll react to that pink python if you pull her tonight. Try not to kill her though, won't you?" He said something like, "Ha, I'll do my best" as he pulled his massive member up and back into his trousers.
Sure enough, they left together about a half hour before the rest of us that night. Her flat actually just across a landing from mine at our accomodation bloke, and I could faintly but clearly hear her gasping and moaning on-and-off for a good hour-and-half or more as he he put her pussy through its paces with his prodigious endowment that night. There was no mistaking it, because they were the same gasps, moans, and guttural grunts I'd prompted from her a year earlier, but markedly more vocal and intense. I had at least a couple of semi drunken, half-asleep wanks to the sound of her pleasure as I forced myself to stay awake just to enjoy how much it turned me on.
Feigning ignorance, I asked her a few days later if he was the same lanky, long-haired kid our friend had described in awe a couple of weeks earlier (knowing fully of well of course that it was). She laughed shyly and silently before confirming that it was.
"Wow", I replied understatedly, with a smirk, continuing: "how was he?"
"Erm, okay?", she said, laughing shyly with embarrassment again, and adding, "he lasted a long time."
"Just okay?", I probed.
She laughed even more, eventually composing herself to say "Alright, we had a good night"
"Yea, sounded like it from what I could hear in bed across the landing," I replied.
"Stop it!.... Oh my god, it wasn't seriously that loud was it?!"
"Yep."
"Oh my god.... Well, it was really really like, deep and intense!", she protested, justifying herself.
"I bet it was. How much longer was he than me?" I asked.
"How would I even know! I didn't get a ruler out! I wouldn't answer if I did!", she laughed.
"Mine's eight inches if that gives you any idea," I offered in hope.
"Well I did ask him and he said he was 9.6" when he measured himself. He said he's sucked it a few times. It didn't feel like he could quite get it all in and it really hurt when he got deep a few times."
Based on his flaccid size at the urinals, I was surprised the figure wasn't higher, and found it almost anti-climactic. He must have been a huge shower, sporting a strong semi in the gents, or my eyes had deceived me. Either way, the better part of ten inches long.
"Wow," I said. "Mine's long but I've only ever managed to lick it. How many times did you do it?" I asked.
"Two or three," she replied coyly, adding. "He wanted to do it again when we woke up but I had a bit of a tummy ache."
"A tummy ache?", I asked innocently, but having a good idea why.
"Yeah", she replied with a mildly impatient, embarrassed look. Enough said.
In other words, she had a tummy ache from the rigours of the punishment he'd subject her pussy (and from the sounds of it, everything up to her whom) the night before. I wasn't surprised at that.
I didn't see hin around again that much after that, and they didn't hook up again to my knowledge. I'm sure she would have liked to. Apparently he was a fresher and had a girlfriend back home, but he inevitably got a reputation around the university campus for thrusting it in and out of other people's, and spoiling one or two young relationships along the way with his remarkable prowess. Inevitably, his size wasn't a secret for very long...