How do you think Duke would act in relationship? I have few headcannons and I have read some of his comics (still reading too!) but I'm writing a fic and I really want to avoid mischaracteriztion for him. (Like in wfa) I really love this character with my whole heart and you obviously are an expert.
The only example that we can point to in canon is DukeIzzy! (& tbh I barely put any stock in WFA at this point, it's fanon-y & just ok as a starting point for new fans, but the test will always be if they make the switch to actually reading comics or if they stay in the fanon bubble)
It's heavily implied that they start dating partway thru WAR and are still together through BatS & Secret Files. With WAR it's a bit tricky because we don't get it stated Out Loud, but I'll give you a few panels here & encouragement to read them in their full context:
(We Are Robin #11 (? Forgot to keep track of this one))
Duke is very physically affectionate with Izzy! And it's to a point where as you're reading, you'll see that Riko has a bit of an implied envious streak. (& yes, it's envy, not jealousy, I double checked lol)
I bring this up because later in Batman & the Signal (#1 below)
^Izzy finally verbally confirms what was implied in WAR before. But these issues lack the overt physical affection from before. Possibly because Duke & Izzy are being mindful of Riko’s presence? Potential discomfort with PDA when friends are known to be near vs before when there was more anonymity by being in more open public spaces where some forms of PDA would be acceptable? Much to consider…
By Secret Files, they're back to some PDA (Cass had just left the Hatch after sparring with Duke so they're relatively alone here):
She's a little worried for him towards the end of this issue as Duke self-isolates a bit. But given the day he had, it's understandable, a bit worrying, and great angst potential imo. Duke’s learned to be very self-reliant over the course of his training, and when that in turn starts to affect a characters relationships it's always 🤌 great. I love when characters 'backslide' & relearn that they gotta let ppl back in 💛 (which kind of gets covered with the Outsiders helping him out in the Urban Legends arc, but goddddd do I wish it was a proper like 6-8 issue arc and not a 2-bit and done thing :/
Anyways, comfort levels with PDA is the easiest thing to point to when it comes to a visual medium, but obvsly it's not the only thing to consider when writing ships. I would say Duke in all of his relationships is very straightforward with whoever he’s talking to, Izzy historically has been no different (with the exception of when he pulls away from everyone at the end of Secret Files). Whether you're writing DukeIzzy, an Xreader or some other ship, I would say getting a feel for Duke's voice first will be one of your best bets. Consider how he interacts with Izzy & others around him. And then tbh go nuts.
No really, I love multi shipping as much as the next person. Anyone who's read my fics knows I love just taking these characters like dolls & seeing what they can do. How far can we push these characters and still have them feel in-character is THE question of fanfic and everyone is gonna have different answers to it. (& some of them disregard the question entirely imo and more power to them lol) If someone is being a jerk, block them 💛