BatLantern marriage of convenience
It starts pretty early, after the first few years of the inception of the Justice League
Hal's been a Lantern for a while now, but now he's specifically a part of a Earth Team which means he needs to check in with Earth more and more frequently which means he needs a home and money and all those things
Bruce who is sick of all the people of Gotham wanting to bed him and the pressures of society to just get married already- it all distracts from how he could be helping the city more, plus there's certain things that aren't available to him unless he's married- certain tax benefits or a portion of his parents will and assets that only get relinquished to him once he's married (since they didn't expect to die so young)
Hal who marries Bruce so that he can stay in the Manor whenever he's on Earth and not need to worry about taking care of an apartment that he rarely visits, and who no longer needs to worry about getting fired from a job for his weird work hours as a Lantern
Bruce who marries Hal for tax purposes and to get other people off his back about being in a relationship
They get married in Vegas because Hal always thought it'd be funny to be married via Elvis and Bruce is still young and free enough to think its funny and agree
Only the main founders of the League are really aware of it because they all attended, but by the time the Justice League is what it is Now the fact that Batman and Green Lantern are married has sort of faded into the background as information that people don't really know. (Plus, who gives a shit that Bruce Wayne has married this random man named Hal? What does that have to do with Green Lantern?)
Batman who is known to have money and so someone asks him for a loan and he's like "yeah, sure. Lemme just check with my husband first." And the other person is like "hus- check- sorry, excuse me what?" and bruce is just like "Its a marriage of convenience but regular things still apply. half of what belongs to me belongs to him so I have to check with him" and that wasn't at all what the person was asking but okay
For the first few years nothing big changes, Hal barely has time to drop by Earth much less the Manor, so they don't see each other that often. They check up on each other through reading logs, and slowly that transitions into sending each other letters.
Just small things, updates on how the mission went, the most recent case Bruce had, what the weather is like in the Anastasia Galaxy. Then it slowly shifts into talking about their days, what their favorite foods are, how they like to sleep at night, what some of their favorite songs are.
Hal gets a message around three years into their marriage that reads "I- or I suppose when you return home to sign the documents it will be we- have adopted a son. His name is Dick. His parents were murdered in front of him. Please don't be afraid when he appears." And Hal just nods and nothing feels wrong about Bruce casually referring to the Manor as home.
He does go home, eventually, and signs the adoption papers, and says hi to Dick.
As a few more years pass, he's needed less and less outside in the galaxy and the reigns are loosened a little more, so he spends more and more time on Earth, and more and more time at the Manor.
They're not a regular couple by any means, but the 'guest' room in which Hal stays always has the windows cracked just slightly, the way he described in his letters, and the duvet is always fluffed. Hal wakes up early and makes coffee for himself and sets Bruce's mug on the counter where he can easily grab it before heading down to the cave, and makes breakfast for Dick before he heads off to work. His information works just as easily as Bruce and Dick's does in the Manor network, and he's stopped thinking as everything inside as "bruce's" and more of as "theirs"
When Hal is off on a mission somewhere a few years later he gets a text from Dick that reads "Fuck Bruce" and then a phone call from Bruce asking him to please come back, he doesn't know what he did wrong
They're just a marriage of convenience, but Dick is still their son, so Hal flies home and they talk and work it out and he comes home to his Dad and cries into his arms.
Bruce whispers his thanks into Hal's hair when they hug goodbye and Hal can't really remember when they started doing that, but he likes it all the same.
They still see each other at Justice League meetings and sure, Bruce stands next to him and asks him how the mission was and tucks his cape around his shoulders in a way he probably wouldn't do normally, but they're married so something is expected of him, right? And Hal just shifts to lean his head against his shoulder and asks after his casework because they live in the same house and talked about it over dinner with Dick last night, that's all.
When Hal gets a message two days into his next space mission that reads "I found a boy" his captain doesn't even say anything when Hal heads home early, to meet Jason Todd.
He doesn't get missions that take him far from home for a few years, and Jason and Dick are the sweetest boys he could ask for. Hal's closet consists more of Bruce's old clothes than any of his own things, but that's just because he didn't really have much and the billionaire did, not because they're so comfy and Hal likes feeling Bruce's warmth. They have a weekly movie night and sometimes Hal stretches his legs onto Bruce's lap and the other man gives him a feet massage while Dick and Jason squabble over who gets to sit next to "Pa" and "Dad"
Hal is off world and missing his family- his two boys that are his sons despite sharing no blood and the man who is kinda... turning into his best friend- when he gets the message about Jason.
He flies home immediately.
Bruce wakes up screaming from nightmares and Hal rushes into his room and holds him, soothes him, cradles him until he calms down and then Bruce wraps his arms around Hal's waist and whispers "Stay" and how can he say no?
The 'guest' room becomes less and less frequented and it isn't until Hal goes looking for one of his old missing socks and realizes he hasn't slept in 'his room' in a solid year and a half, now.
He's taking a walk with Bruce through Gotham- Bruce's coat draped around his shoulders and the other man a warm and familiar presence at his side- when Dick calls them both, frantic, claiming that a small child won't stop following him. Bruce and Hal exchange glances and before the night is over welcome a young Tim Drake into the Manor.
It's a marriage of convenience but it starts to feel almost dangerously like more when Tim nearly dies and then Hal is faced with a young and snappy teenage girl and Bruce, who snarls just like her.
Steph doesn't last long as Robin, but she still floats on the outskirts of the Manor and comes over for dinner and it isn't long before he and Bruce are teasing Tim about picking out a ring and the teenager is blushing and complaining 'go away, dads'
The house grows a little empty as they trickle off to do their own things, but Hal is still there, and Bruce is still there, and its almost like their younger years again, with Bruce cooking and Hal doing the dishes only this time they're both here, not rushing off to other planets or slaving away at Wayne Enterprises
And Bruce is fun, Hal realizes as they sit at the table made for ten, knees touching and trading wine glasses and stories and laughing.
They watch a movie and Bruce falls asleep with his head in Hal's lap, Hal's fingers combing through his hair and rubbing along his back and Hal starts to think 'oh no'
And it's been creeping on them for years now, probably since Jason, maybe even since Dick, but neither of them mention it when Hal has an accident and it isn't Batman who stays by his bedside table but Bruce, holding his hand and fixing the pillows behind his back and sneaking him Batburger when the shitty hospital food can't sate his cravings.
Neither of them says anything when Bane breaks Bruce's back and it's Hal- not Alfred, or Dick, or Clark- who wheels him home and helps him relearn to walk and feeds him and holds a straw to his lips and tucks him into bed and stabilizes him with his ring and holds him when he wakes up crying from nightmares
Cassandra tumbles into their lives at some point and Hal thinks Bruce was made to be a girl-dad and wonders when in his head he stopped thinking of him as 'Bruce' and simply considers him 'you'
Bruce calls him 'husband' and 'my love' as a joke that started from Elvis, and Hal calls him 'sweetheart' and 'baby' and 'babe' and its just for the crowd, just so that people believe them when they say 'oh, I love him so much' 'he brightens my world' 'I've never been happier than since I met him' 'hes the love of my life' 'my soulmate'
And its Hal who consoles him when he breaks down and tells him about Talia, about Ra's, about what the League made the two of them do and it's Hal who holds Damian when he arrives for the first time and whispers to him that he will do great things, just like his father
And the children grow and come and go and Duke is sweet and funny and sarcastic and Bruce says that he 'gets it from you' and Hal quips back that 'the rest all got it from you' and Duke rolls his eyes at them and says 'I can't believe you guys are real' and something twitches in Hal's chest
"It's a marriage of convenience." They tell any of their friends who will listen, though those friends have long since stopped asking or teasing them about it, have just grown to accept that they will always be each others plus one.
"It's a marriage of convenience." Hal reminds himself when Bruce gets sick, so sick that he can't walk, so sick that he has to give up Batman, so sick that he's confined to bed and Hal has to feed him and clothe him and bathe him and keep him alive.
"It's a marriage of convenience." Hal whispers as Bruce's chest stutters with its last breaths, as Bruce's hand grows limp and cold in his own.
"It was a marriage of convenience." Hal tells the world, standing behind the casket of midnight black, wearing Bruce's clothes and the cologne Bruce got him and the sorrow in his voice is only there because of the happiness Bruce gave him before.
"But somewhere along the way, it became real."
