Kink means two things, and those meanings are being blurred a little by the kink_bingo game. Kink is often taken to mean non-standard sexual practice, usually associated with BDSM. That's what we mean when we warn for kink in a story header. But kink as fetish is broader.
I didn't label a ficlet with Giles having sex with a pregnant Jenny as kink, even though sex with pregnant women can be a kink. In that case, it was just a thing two people did, not a fetish for him, not something he sought out because it made him unbearably excited. Outdoor sex, sex with food, tickling become kinks when they're something that carries extra emotional and sexual charge for the characters. (Compare hurt/comfort as fic kink.)
The point of kink bingo is the fetish. Each prompt is supposed to be the sexual focus of the response fic.
That Giles/Jenny ficlet couldn't be a response to a hypothetical pregnancy-sex kink prompt, because it's not a kink there. And, to be honest, my response to the voyeurism prompt isn't a proper response, because the voyeurism is incidental and not front-and-center as fetish. I'll need to write another one, probably all about the kink every Watcher has. Cough.
Kinky fic in the non-standard-practices sense is popular these days. Is there really an urge toward the transgressive that slash is no longer fulfilling by itself? More likely it's just that we're all interested in sex, and fantasies range further than practice (because they can safely do so). And also commercial products aren't coming anywhere close to scratching our itches. I just advanced this theory to Mr Pedia: Commercial pr0n sucks because it's not about people we care about, and if it takes the time to make us care it's probably stopped being prawny. We come to fanfiction with love for the characters already in our hearts, so it's got a huge advantage.
This is maybe the ur-example of the id vortex in action, I guess, that fanfic so often chooses sex as a way to explore character. And character is what we're most obsessed with. That goes for kink-sex fanfic too. If it doesn't come from character, if it's not rooted in the people we got to know on screen or in the book, then it's not fanfiction for me. It's bodyfic, or pose-the-action-figures fic. But then another story can be the hardest core and the weirdest AU, and if the characters are themselves in some deep way, I'm satisfied.
I'm a firm believer in the Many Worlds Interpretation for fanfiction. A multitude of interpretations can coexist in story. Thousands of stories from hundreds of authors, each visiting another world. And the coexist in my own head, for that matter. Many storylines and variations play themselves out in my head every day. But I can't stray from my core concept of who the characters are.
I freaked myself out with my first full draft of "Rough Boys". That's not Xander, I thought, and that isn't Giles either. I came pretty close to deciding I couldn't write any kinky fanfic with integrity. I then backed up, rethought, and found a way to fit the setup into my understanding of the characters at a particular point in canon. Draft 2 depicts them as I know them, not as posed action figures. I probably stretch Xander considerably further than I ought, but he's rubbery. He'll sproing back.
As I was thinking about that, I realized that it was silly to think of that problem as purely a kink problem. I've seen lots of vanilla fics that run roughshod over characters in their rush toward soppy romance and the author's preferred ship.
Therefore, I joined the hordes in kink-bingo-ing. I've now written five stories for my card (links all on that page). I've already written the prompt that intimidated me most, "watersports", and I went for comedy. This is a copout, because the point of kink_bingo is to make it sexy. And it's never fun to watch a writer flinch. You can always tell when the writer is backing away from the material and not really committed to it.
Of the remaining prompts, only two are baffling me. One is "double penetration (one hole)". I know it's a real-world porn trope, but I find it absurd and icky. Also, the choice of the wonderfully gender-neutral "hole" there is anti-sexy for me. Oh well. "Plushies/furries" is an example of something I find so far removed from sexuality that I'm puzzled how to to approach it that way. Writing that one will be an exercise in writerly empathy and entering into the heads of others. The challenge is to sell it, so you have no idea I'm not in the least turned on by stuffed animals.
That's always the challenge, truthfully: to hide my own responses to many things. Though of course it's impossible, because my core values inform every choice I make, and everything I write says to you, this is how I think the world is, and this is how I think we ought to live in it.
And apparently one of my core values is plot, because it keeps happening, even in kinky prompt responses.
Plans, plans, plans! I haven't wittered about fic in at least five minutes.
"Glory holes" and "humiliation (public)" I'll probably write as Giles/Ethan preseries, with a sadistic Ethan. I cannot stretch Giles in my head into somebody who'd choose either of those experiences himself.
"Caning" is one kink in a longer story, also Giles/Ethan pre-series, in the Blackmail storyline. I've alluded to this story before.
"Exhibitionism": either Xander having fun in the Attic storyline, or Giles himself in a "Band Candy" missing scene, with Joyce. The latter would be a ton of fun. Yum. I think I'll go with that one.
The rest are likely going to be in this new G/X storyline, the stories set in the attic in Cleveland.
"Hand fetish" is in progress. Giles/Buffy smarm, following hard on the heels of the "knifeplay" response. Thanks to shitsu_tonka's suggestion, Giles's right hand will likely be damaged, probably because of injury long past. "Tattooing" is also in progress, and is the place I really wanted to get to in that storyline. Following that is a more frivolous and straight-up prawny response to "bondage".
I'll likely post everything I can finish for July 26, my second summer_of_giles day. After that I'm not signing up for any more date commitments. I'm just going to finish things as the subconscious wants to finish them. Eventually I'll get bored with that, but I'm going to give it a nice long break and see if I can finish some serieses.