Kinky is really just a state of mind. I'm sure that lots of people here have been in a situation where they went past what they thought they would do because of the person they were with and the "heat of the moment". As an example, consider "rimming" or "salad tossing" or "ass play" (you can often tell someone's age by which term they use). I never thought that it would be something that I'd want to do, but then one day, along comes a hottie that can't get enough of my tongue, and I'm licking and stroking everything between her legs because of how incredibly into it she is, and how her reactions turn me on so much. Eventually I'm letting my tongue go lower and lower until she's squealing and trembling with my lips on her bottom. I felt like the star of a porno with her reacting to every slight twitch of my tongue. Why would I not want to do that for her.....especially with how much of a turn-on it is for me that I can do it for her. Does that make me kinky, or her kinky for having me do it for her? I don't really care. It's all about the interaction between the people involved. How many girls would go down on their guy if he refused to kiss her after she did it. If you find something repulsive, don't do it. If you don't, and your partner doesn't either, sooner or later your curiousity will get the best of you.
For some people, having sex with the light on is kinky. Others may have lots of toys and stuff, and find that they don't actually use them all that much because the sex is fantastic anyway, but they're there if they want to try some new stuff. (I'm kind of like that myself) It's all about how it makes you feel, and not just physically.
I think the situation is paramount to one's definition of kinky. (want to watch a porno with your parents.....or that hottie from the gym?) And I also believe that society in general is placing a lot less negativity in what two adults choose to do together than they had in the past.