It's pretty hard for any site these days (especially the big ones) to stop fake profiles and scammers from signing up, but I think I get what you're after.
The last one I haven't actually reviewed fully, but the site owners took the time to add a profile on this site. We've picked out the 12 best dating sites for you to try – and there really is something for everyone.No longer embarrassing or, God forbid, cringe, half of all single people now use online dating sites to find love (or at least an easy hook-up... In fact, one in five relationships now begin online, with Tinder alone matching 26 million people a day.Stephen asks: "I am trying to find a 'real' adult dating site. The people on there either do not exist or are trumped up.It seems all that I have come across do not have real/true information... I sent the company an email to complain, but they didn't reply.
And when I clicked on a picture, the city and/or state changed to someplace nearby... There has to be a legitimate adult dating site out there. "Hi Stephen, and thanks to my colleague Cory Silverberg (About.com's Guide to Sexuality) for sending you my way.
To answer your question: it depends on what you mean by legitimate.
Are you looking for an adult dating site that caters to adult encounters or casual sex, that isn't full of scammers or fake profiles?
If that's the case, I'll admit its pretty hard to find.
My first recommendation would be to try Lavalife's Intimate Encounters section; you sign up with them and then decide which of the three sections you want to be a part of (Dating, Relationships or Intimate Encounters).
You can use different handles in each section under the same account too, so no one will be any wiser if you want to advertise for one thing in one place without ruining your chances for something more should it come up.