If 14" or even 12" cocks existed we would have seen a video by now. Imagine there are guys of that size, some would have hidden them away out of embarrassment but a few would strut around in locker rooms in the way that is often described in these forums. The biggest i've ever seen 'soft' had to be a good 8" and he really liked to show it off, as did most of the guys in my school with anything to brag about, for those guys any excuse to stride up and down was jumped on. I only ever noticed one really big guy who didn't do this and he wasn't exactly trying to hide it, just acting like everyone else as if it was no big deal. If i'd had 10 flacid inches I'd have been showing it off, as would most guys I believe.
Let's imagine there are guys out there with 12"-14"
The majority are straight and, like most of us, they end up in a relationship. We all know most girls like a big dick, a few like very big dicks and the girls that dig these theoretical 'beyond huge' guys are going to be girls that are really into sex.
From looking at porn most (all?) of these rare 12"+ cocks are going to be too long to fit in a pussy and they are likely to have trouble getting an erection. Some of those highly sexed nympho women that just had to sample the huge dick would eventually get sick of the pain of being fucked too deep, the frustration of having to fuck a semi, of never having a guy's pelvis grind against her clit, of delayed or non-existant repeat performances so some (most?) of those relationships just won't last. Those guys are going to be back on the market again pretty quickly.
So, in these days of hook up sites there should be a few 12" monsters looking for women and women keen to experience them. Even guys who had never successfully had sex could probably get some action: "Shy virgin, 13 inches seeks experienced lady for whatever" would undoubtedly get a reaction from a few women.
So, some of these huge guys who showed off in the locker room, get compliments from strangers at urinals and glances at their bulges would be visiting size queens for casual sex. Some of those girls will be exhibitionist sluts and be happy to let a guy point his camera phone at her face (maybe wearing sunglasses) as she plays with it. This happens a lot, check out the 'amateur girs and big cocks' thread in the porn section. It's full of cocks similar in size to Mandingo but none close to a convincing real life 12".
12"+ is the preserve of low res solo masturbators (rightly dismissed as prosthetics) and some fairly convincing still pics. If any of those were real we'd have seen an HD movie of a woman working on one with both hands and her mouth by now.
In the meantime, look at porn, When I signed up to this site Mandingo had undoubtedly the biggest fully functioning cock in the business, eight years later he still does and there are people on this site who don't even believe he's a real life 9"
Either the beyond huge ones don't exist or owning one isn't as much fun as we'd all like to believe.