Oh god you are opening one hell of a can if worms--
I have been compiling this for the past 3 or 4 days.
Alright so these regard the Las Nevadas era, obviously
Let's start off with the easiest: Quackity's dominant, Wilbur's submissive. They don't switch it around, at most the sometimes have vanilla sex without much of a dynamic, but it's always there at least a little bit.
Another thing that's very stable is that Wilbur's a massive brat. He doesn't always push it to the maximum, but there's always some playful quips and jabs - partly also cause they just like to playfully argue (iT's iNtEllEcTUaLLy StiMuLaTiNG), but in big part cause it provides a genuine reassurance that the relationship is stable and that they're in love and that it's not just some fling. It serves as a little confirmation for both of them, but it's especially important to Wilbur. Yes, Quackity loves the challenge, as well as the whole "you can struggle as much as you want, I'll still break you" thing, but for Wilbur having Quackity put him in his place is like air - he basically needs it to survive. As I've said many times before, that man for absolute sure has bpd, so he needs a lot of reassurance that he's loved and cared for - and bratting is a great tool for that. He can act up, be rude, disrespectful, misbehave, and yet at the end of the day Quackity will still completely break him, and metaphorically and literally shove his face into the mattress so hard he can't speak and can only nod obediently. And what's especially important is that no matter how hard Wilbur misbehaves, the very second he's broken and forced into submission Quackity will absolutely drown him in the most flowery of praise, calling him the best boy, telling him how proud he is of him, how good he's being, etc, making Wilbur just completely melt into a massive puddle of happy tears and cum/hj
On that note, they're both heavily into praise. And I feel the need to mention that all of these are very two-sided. It's common to talk about how subs love praise, but I've never really heard anyone talking about how intense of a feeling it is to just verbally pour out all your love for someone in a series of compliments, praise, affectionate pet names, etc. It's very much something they both love, not just Wilbur.
Another thing: kinks very frequently bleed into each other. Good example is that while the praise is obviously positive, it can also just as much serve to humiliate and degrade (sometimes at the same time), which they're also into. This can range from Quackity calling Wilbur his "princess" or "good slut" to just full on insults.
Next one: worship. Quackity's heavily into that one - similarly to how Wilbur's into bratting (btw this one's very entangled with the power play). The man is heavily traumatised, he has severe abandonment issues - he fucking lives for all the begging, all the "I need you"'s, all the expressions of that complete and utter submission (after the bratting, of course/lh), the eagerness when Wilbur begs for permission to pleasure him, and all the other ways to just basically straight up worship. "Sir" is used on the regular, but even the slightly more 'cringy' titles - when said with enough undying devotion - such as "master", "lord", or even "god" in the context of practically moaned-out confessions like "you are my god, I need you" are a sure-fire way to basically make Q hard on the spot.
Things like primal play and consensual non-consent they're casually into, but less so creating elaborate roleplay situations, and more so incorporating it into their normal play - for example wrestling with lots of scratching and biting until Q's got Wil pinned down, as well Wilbur whimpering/crying/screaming things like "no" or "stop" deliberately instead of safe wording during like idk overstimulation for example.
Same with wax play, electro play, fire play, knife play, gags, bondage (they really enjoy the bonding (pun intended) experience of just fancy shibari - like, they just talk and joke and laugh and flirt and just enjoy each other's company as Quackity tries some elaborate, complicated ties and knots on Wilbur; it's quite sweet and wholesome, actually); they'll basically try pretty much everything, just cause why not.
Breeding kink. For Quackity it's tied in with marking and possessiveness (he absolutely loves leaving marks all over Wilbur in a way that's very visible). And similar for Wilbur - he just loves the feeling of Q finishing inside of him, whether it's anal or oral. It just serves as a reminder that he belongs to Quackity and makes him melt completely. Frequently he insists on shoving a but plug inside himself afterwards, and gets very vulnerable and soft, and simply requires love and cuddles and the sweetest words and praise - which Quackity is more than happy to provide.
They're also exhibitionists, but like, they don't do anything where there's an actual risk of someone seeing them. It's more so, for example, fucking against the window in Quackity's suite, that's like, 8 stories off the ground and there's no chance anyone could actually see them.
Masochism - they're both masochists. With Wilbur it's more broad, but Quackity also loves that thrill of pain - particularly when it's from his lover's nails digging into his skin from how intensely they're fucking (partially touches upon that worship thing too); and when I say "nails digging into his skin" I mean like having to change his shirt the next day cause he went to work and then someone asked him what are those small, linearly distributed reddish-brownish spots on the back of his white shirt. There is blood. Wilbur's just altogether a masochist. He just absolutely lives for the way pain heightens all of his senses and how intense it makes the pleasure that follows right after. There's also the added bonus of power play, humiliation, submission as well as being forced into it, etc.
Sadism - Quackity is a sadist through and through. There isn't much there to say, he just absolutely loves it on so many levels, and both the physical, as well as mental sadism. It yet again connects to the power play and such, but not only. Tldr tho is that he just genuinely gets very turned on by CONSENSUALLY causing pain - not to get into a big rant rn, but that's something he really struggled with internally. He was aware of the mainstream side of BDSM, but he only really got "into it" with Schlatt - only issue is that Schlatt wasn't dominant, he was domineering. What they did wasn't actual BDSM, cause that requires mutual care, respect, informed and freely given consent, etc, which wasn't the case in their relationship (not gonna get into too much of my analysis here but I have a lot of thoughts). Nonetheless, that kinda "opened the door" to that world to him, and long story short he began realising he could be very into it, just not in a way that was forced on him by Schlatt. He vaguely and subtly tried bringing up the topic to Karl and Sapnap ("ha ha look at this movie guys ha ha isn't that craaazyyy" kind of vibe), but the two seemed pretty repulsed by the sheer idea of hurting someone you're supposed to love, so Quackity immediately dropped it and never came back to it.
And then there's Wilbur. It didn't start off sexually, at first it'd just be Quackity bluffing to threaten Wilbur, but then the guy would just be like "bet", so Q couldn't back down. And then gradually it became apparent that Wilbur can very much handle a beating - hell, he was searching for it - and that he very much prefers rough sex. And so they happily introduced violence into their sex life.
Also, connected to sadism and masochism, they're obviously heavily into impact play, "wrestling", as well as just straight up Wilbur getting beaten up in various ways.
Now, on the topic of character analysis and such: positions. Believe it or not, I actually don't think Q's always the top and Wil's always the bottom. Wilbur definitely prefers bottoming - hell, he absolutely loves it, it like legitimately borders on a fetish for him - but he'll be fine with topping every now and again, so long as he can serve his partner. Quackity, though, I believe to be a verse, actually.
See, the way I see it is he's short, has longer hair, is very attractive but maybe not in the most "macho" way, has a big ass, etc, so I do think throughout his life he'd be the designated bottom (and sub, even in vanilla situations to a degree). With Schlatt he obviously bottomed and subbed, and I won't be getting too into it, but - tw - it frequently wasn't consensual. Essentially Schlatt "was supposed to have access 24/7", so to speak.
So Q's got trauma. Quite a lot of it.
During his marriage with Schlatt he begins hooking up with Wilbur. And Wilbur cares a lot more, and respects him more, but Quackity still just defaults back to what happens with him and Schlatt, cause "see? he wants it. it's ok. it's good. there's nothing bad happening. Schlatt can't hurt him, if he's doing something that Quackity wants" - pretty normal trauma response, but it does end up just solidifying it all in his head.
He gets with Karl and Sapnap and by that time he is aware of his trauma, but he's got this mentality of "I'm broken, i need to be better for them. I need to fix myself. They deserve better than to be my caretakers or some bullshit like that. I'm not a snowflake, I can handle it by myself". So he makes himself bottom (even though there's not really that much of a need for that, and they could work it out differently no problem), which usually sends him into massive panic attacks, although he'd learnt to hide those masterfully by then, and he ends up basically retraumatising himself over and over again. But even with those insanely impressive acting skills the other two can feel that something's off, plus Quackity by himself just starts to subconsciously avoid sex. The lack of communication weighs on all of them, and it's just one of the reasons why they drift apart.
After revival Quackity and Wilbur eventually start hooking up, but this time with Q topping. The "saving grace" is that even though he does love Wilbur deep down - more than anyone else, though he repressed it immediately - they both are this safe space for each other where they can be just the worst versions of each other. It's toxic, but it's free. So Quackity gives Wilbur an ultimatum: if he wants sex, Quackity's topping. Wilbur takes him up on the offer, and that marks the moment when their shared healing journeys begin.
After a long time of building love and trust and care in the relationship, Quackity slowly begins to occasionally ride Wilbur, and that develops slowly, until they comfortably regularly switch, though most of the time Q's still topping, and Wil bottoming. They always keep the dominant/submissive dynamic the same, though - it's what makes Quackity feel safe enough to try getting outside of that comfort zone in the first place.
UHHHH AFTERCARE! RIGHT, AFTERCARE-- I'd say they just cuddle a lot. Like, pretty much always they just both need that physical comfort of touch and cuddles. Depending on the scene that can be in a bath, or even sex by itself can be part of the aftercare (when used as aftercare, it's always very gentle and careful and loving and full of sweet words and praise and "i love you"s), but on the whole I'd say that they always engage in some tender, loving, caring, physical contact as the primary aftercare, and then also words of affirmation, physically taking care of each other's possible injuries, etc.
Istg if I forgot about something I'm gonna strangle myself, writing all of this took me so long jfc
