superbat medieval arranged marriage au where duke bruce wayne has been promised to king kal-el since kal was born. the proposal was created by zod after kal's mother died during childbirth, his father following soon after. although the waynes have power, they cannot deny the royal family outright, and before they can devise a plan to get their son out of the arrangement, they die.
zod sends kal away from the palace to live with some humble farmers the moment he's sure the infant will survive the journey. he rules the kingdom as he likes, while kal grows up hidden in a small village. when kal (who likes to go by clark, but can't with his royal title) becomes old enough, zod sends for him, eager to mould him into his interpretation of the perfect king just under a year before he is set to marry.
the time comes, and bruce goes into it absolutely abhorring king kal before they even meet. kal has had plenty of time to call off the marriage, to leave bruce to gotham, to his new son (dick), to the gutters of the dukedom the kingdom has failed to serve, the place bruce protects ruthlessly every single night.
he manages to be polite, if only because of alfred's many lessons in propriety during his boyhood. and also because the king possesses a physical power previously unheard of, and bruce won't risk dick's life by angering him. the wedding happens. bruce refuses to bring dick despite his begging, keeping him in gotham and far away from the palace.
bruce makes it clear he has no interest in consummating the marriage, and the king, curiously, seems horrified at the implication that he would do such a thing. bruce sleeps in the sitting room instead of in the bed with kal, who pretends he can't hear his new husband's fluttering heart and distressed noises from the nightmares he has each time he sleeps.
they manage to coexist without much trouble. kal finds that bruce is adept at running a kingdom, much more so than kal himself. zod doesn't seem to like bruce very much, but kal can't deny his intelligence, and advocates for his presence at every meeting.
slowly, very slowly, they start to get more comfortable with each other. kal finds himself looking forward to their shared meals and watching bruce spin his so-called advisors in circles. he orchestrates his writing sessions to coincide with bruce’s workouts, trying his hardest not to get distracted by his husband's powerful bulk or the flush of exertion on his skin. but he never acts on it. he promised bruce he wouldn't attempt anything.
when he can (when bruce travels to gotham to handle his dukedom), clark sneaks out as the superman to help the people of his kingdom. more than once, he runs into the gotham bat, a highly competent knight working towards the same goal as clark. the bat is stoic and curt, but clark observes his kindness in the way he offers starving children money and food. he watches the bat move like a shadow, silent and skilled. he notes that the bat never, ever goes far enough to kill anyone.
more than once, clark has to forcibly remind himself that he has a husband waiting for him at home. a husband that he likes. a lot. a husband that he really, really wants to do things with, but never can.
he's out with bruce in the wintertime, enjoying peace and quiet by a froken lake when they're ambushed. the assailants brandish a glowing stone that brings clark to his knees. he watches helplessly from the ground as bruce fights them off, his movements oddly familiar. but none of it matters when one of the bandits smashes the ice and bruce goes in. clark screams out his name, crawling to the edge and barely managing to grab his hand in time.
he pulls bruce out with shaking limbs, dragging them both over to the horses. the bandits have retreated, but the weakness the stone gave him hasn't. clark only just manages to get them both on one horse, and he rides hard for the kingdom gates.
the doctor says bruce is hypothermic. clark feels guiltier and guiltier with each moment that passes, where he gets stronger and bruce doesn't. he sends for bruce's family in gotham and climbs into bed with his husband for the first time.
"forgive me," he whispers, pulling bruce's unconcious form close and nuzzling the soft hair at his temple. his bare skin is cold against clark's. "i want you to get better. i need you to survive."
he wakes to someone bouncing on the bed, and opens his eyes to see bruce's ward snuggling against bruce's other side with a wide smile. clark follows his gaze to see bruce awake, his eyes alert. clark puts a hand on his chest to feel his heartbeat, stronger than it was before he slept.
"you're alright," he says with wonder. bruce nods, and clark remembers himself. "i can leave you with your family." he pulls away, but stalls when bruce shivers at the loss of contact.
"you can...stay," bruce says slowly. "if you like."
clark would like. and so he does.
things are much better after that. bruce trusts clark around his ward, and clark absolutely adores the boy, frequently showing him around the palace and taking him on small adventures. he and bruce start sleeping in the same bed, and clark can finally soothe bruce during his nightmares. zod seems more antsy than usual, but bruce is helping implement programs for sick and poor families, so clark focuses on the good.
and then clark gets betrayed by his father's best friend, and he finds himself in the city streets, fighting against his own men as superman, with batman at his side.
bruce knew the coup was coming, and had quietly relocated many families to gotham because he knew destruction would come soon. he fights at superman's side (who is obviously kal. who else would have eyes that blue or sense of goodness so engrained into them), and together they fight a gruelling battle. bruce sustains a few injuries through the victory, so he is quick to retreat after the fact and assess the damage.
in a secluded area away from any prying eyes, bruce yanks off the bloodied, cracked mess of his cowl and scrubs at his dirty face. superman follows, because of course he does.
"batman? are you here? i saw you get injured saving that child, and i came to see if you were all right—”
bruce freezes in the clearing, wide-eyed and nervous with no feasible way of escape.
kal mirrors his expression. “bruce…?”
bruce swallows, wets his lips. kal’s eyes follow the movement. “kal—” in less than a blink, kal has crossed the expanse of the clearing and cups the back of bruce’s head, tugging him close for a searing kiss.
before bruce can reciprocate, kal pulls back, an apology on his lips. “sorry—i’m sorry. you said you didn’t want this, m’sorry.”
but bruce snatches his red cloak in one strong fist and pulls him back, murmuring against his lips, “forget what i fucking said. you’ve been holding yourself back this entire time, haven’t you?”
