votes by Anon User, Anon User, Erik Madsen, Wilbert Lau, and others.

There are a lot of interesting aspects to it, and I'm sure my experience is different from that of others, but I'll relate my story here since I was asked to answer this.

I dated a model during what you might call her "declining" years.  I put that in quotes because to a normal person the idea is absurd.  Models have a shelf-life of maybe 10 years, 15 if they are lucky.  Once a model hits 30, the modeling industry considers her old and used up, and there is no shortage of eager 15 and 16-year-olds from Eastern Europe who are willing to work longer hours, fly more places, and get paid far less.  Almost every model in her late 20s (including the woman I dated) begins to worry incessantly (when she isn't worrying about non-existent eye wrinkles) about how to make herself into a "brand" and transition into being a supermodel, which is pretty much the only post-modeling career available to you in this line of work.

Dating a model is pretty interesting.  As a couple and as a man, you are immediately accorded utterly absurd amounts of social consideration.  Any time we were out, we'd get special treatment.  Not just from service people but just regular people.  People would regularly offer to let us cut in front of them in lines at restaurants, grocery stores, even once at the DMV (!) when we happened to go together.  Of course we could get into clubs, although this is not as great as it seems because every two-bit wannabe pickup artist would try to chat "us" (really just her) up when we were just there to dance and have a good time with friends.  Probably the biggest benefit is that we always stood an extremely good chance of being offered upgrades to first class when flying.  Airlines look for well-dressed people to offer first-class upgrades to when seats are open, and dating my girlfriend had led me to up my game in terms of dress so I always wore a jacket and tie when flying, so we were a pretty good-looking couple (well, she was - I was a chump in a nice suit), and we would always get offered the first-class upgrades.  And we flew a lot, because my job is pretty portable and she would have shoots all over the world.  I eventually decided that dating a model was potentially a cash-flow positive arrangement in that during the seasons where we traveled frequently enough, the value of the first-class upgrades we would receive (sometimes thousands of dollars) actually exceeded the amount of money I spent taking her out on dates or covering for her fraction of the rent (more on this below).

Speaking of money, her finances were always a mess.  I've heard this is often an issue with people who work in industries where you get irregular lump-sum payments for your work like writers and actors, which modeling is very similar to in some ways.  She would get huge checks every few months but on a highly irregular and totally unpredictable basis, as she was always a contractor she would be responsible for handling her own tax withholdings (which she would never do), so she would always have a huge unexpected tax bill in the spring which she would freak out about and each time she was only saved in the nick of time by the next check that (luckily) came in the mail.  I was brought up to be pretty good with money so I tried to help her keep her finances in order, but she never understood why she should put away ~45% ("That's like half my earnings!") from every check to account for the self-employment taxes that would be due at the end of the year.  After being together for a couple years, I got a good sense of how much she earned over time and tried to explain to her what she should try to think of as her average income stream over time and to keep weekly expenses in line, but it was something she just wasn't very interested in.  Instead she would go on partying and shopping binges in the weeks following her getting paid and the rest of the time scraping by when she wasn't.  Luckily, I made the wise decision to keep our finances completely separate even when we started living together and "splitting" the rent, which more often than not turned out to be me footing all of the rent for that month and her paying me back months later when she got paid.  But like I said, sometimes this was offset by the tremendous material consideration in the form of airline upgrades or hotel room upgrades when we would go on vacation.

Ultimately though, the most frustrating thing about the whole experience is that despite being absolutely drop-dead gorgeous (some models look "strange," while others are more conventionally beautiful, and she was one of the conventionally beautiful ones), she became increasingly insecure and worried about her "declining" looks.  To give you an idea of what this is like, imagine someone who is literally better looking than anyone else you know or ever meet on the street.  Not only this but they are, by dint of their profession, an expert in terms of how to dress and apply makeup, so you are basically dating a walking Photoshop commercial.  Despite this, she would obsess about what I could only perceive to be completely invisible fat on her thighs and just as invisible wrinkles around her eyes.  She would literally ask me, "Do I look fat?" or "Don't you think I look old?" and of course as a man with a good sense of perspective about what I'd managed to snag, at first I would enthusiastically answer, "Of course not!  You're the most beautiful woman on the planet!" which as far as I could tell was 100% the truth.  The problem was, none of these really assuaged her insecurities (of course) so she would keep asking over and over, and there is a limit to how many times you can enthusiastically exclaim about how beautiful your girlfriend is, even if you do believe it to be the truth.  Obviously, she noticed this difference in the enthusiasm of my answers, and it didn't help her insecurity about her supposed fading looks.  Remember, again, during all this time she is still better looking than 99.99% of all human beings, so you get a sense of the utter absurdity of the situation.

She was also spending all of her spare time trying to "make it" as a supermodel, which for those who aren't familiar with the industry, doesn't mean "extra-good-looking model," it means models who have the brains to figure out that they have to leverage their looks into building themselves into a brand and business before their shelf-life runs out.  She had several friends who were doing the same thing (models have wised up to the game, with the success of supermodels like Tyra Banks and Heidi Klum who have parlayed their careers into television shows and such), one of them is having some measure of success at it - you would probably recognize her name since she hosts a minor show on cable.  But of course to build a business you need to, at a minimum, be pretty good with finances and she had no interest in it, despite my continuing attempts to try and get her to pay attention to the basics.  It wasn't that she wasn't smart - she just hated finance.  As a result of this, she became gradually more demotivated, insecure, and would complain often that she was "over the hill" which is pretty absurd at 28 or 29 (although I hear it sometimes from Silicon Valley entrepreneurs, which I consider equally absurd) and it became a continual source of negativity in our day-to-day interactions.

I met her when she was 25, and we dated nearly four years until finally breaking up just a couple months before she turned 30.  I know I've sounded pretty negative in this answer, but in the first couple years the relationship was so good that I thought she was marriage material, but her insecurity and negativity became such a problem later on that despite my attempts to be supportive and make it work we eventually had to part ways.  I really thought we were meant to be together so I probably let things go on for much longer than was wise, in retrospect.  At one point I thought maybe we could make it work as a joint venture, with her doing the modeling and speaking and industry relationships, and I would handle the finance and "business" pieces, but her negativity and insecurity about everything had totally poisoned things between us so much by then and I just couldn't handle it anymore.

One funny postscript is that my mom perhaps recognized this before I did, and (to my chagrin at the time) tried to set me up with various hometown girls when I would visit for holidays.  Finally I met someone when I was home for Christmas when my mom, before I could stop her, introduced me as "my son, who is dating the supermodel" to a girl I'd been friends with in high school, which of course got her to talk to me.  She now says she was impressed not because I was dating a supermodel, but because I was helping her with her finances and "good with business," and now she is my fiancee (she helped me proofread this answer!).  That's my story, hopefully it satisfies your curiosity!