Chapter Text
It started out as a joke, and it was supposed to stay that way.
Slade said "I'll get you a collar with my name on it" after one too many times Jason let his insecurities get the better of him. There's probably something more loving or sensitive he could have said instead, but Jason got the message anyway. Knows, at least for a little while, that Slade wants him. And then he shot something sassy back, and that was that.
Until Jason said "if you keep doing that shit I'll buy you a fucking leash" because he really doesn't like when Slade relies on his enhancements to keep him out of harm's way and doesn't give him the time to plan three different alternatives. He especially doesn't like it when Slade jumps into harm's way for expediency's sake when there's another, safer way to do it.
And it snowballed from there.
It became a thing. A thing that still pretended to be jokes but a thing nonetheless.
A thing made of many, many dog themed jokes.
And they don't even stop in public.
It's an easy way to slip vulnerability past any onlookers. Grayson gave him a really nasty look for calling Jason a puppy during a collaboration, but Jason stood straighter after it. It's not the words themselves that matter, it's the reminder. A way of saying "you're mine and that means something". If Grayson willfully stomps all over Jason's feelings he needs to remind his boy that he still has someone backing him up. But he couldn't call attention to it and put Jason on the spot, putting his weaknesses on display. So a crass, tasteless, patronizing joke later, Jason is playing his part shooting some delightfully scathing commentary back, Grayson is taking his side, and ten minutes later Jason is telling his brother to shut the fuck up when he goes back to being a judgey asshole, because now he remembers that as long as he's got Slade in his corner no one else's opinion matters.
Jason will say "down, boy" as soon as he sees Slade deciding to be reckless, regardless of who might be listening. It's become his shorthand for "I will find a better way to do it, just give me five minutes to think it through". Billy once rose a disbelieving eyebrow at him, but he doesn't feel like explaining why it doesn't bother him. The short of it is, Jason won't exchange failure for safety. He's as goal oriented as Slade is, the only difference being he makes more detailed plans to compensate for the fact he can't heal a bone in three days. If he says there's a safer way to do something, he's thinking of it in terms of optimizing resources, not fear of consequences.
It doesn't make Slade feel bossed around, it makes him feel cared for. And it doesn't hurt that in order to keep him safe Jason needs to display his own competence. That's always fun to watch.
Somehow, he still thought he meant it as a joke when he went and bought the thing for Jason. A black leather collar with silver studs to match Jason's biker aesthetic and Slade Wilson engraved on the outside. He thought it would be a fun thing to play with in the bedroom.
And it was.
Only then Jason decided to wear it to a Wayne event, together with an impeccably tailored suit and a wicked look in his eyes that's the best thing he could wear at any given time. The best things always happen when he's wearing that look.
Well.
Best for Slade.
Likely terrible, painful, and horrible for everyone else.
Which means he also started wearing it as Red Hood, because now if Batman wants to protect his secret identity he can't be having public family beef with the guy whose unhelmeted face looks suspiciously like a non-deceased Jason Todd.
Slade loves his devious little brain.
And then Jason went and bought Slade his own collar, only he never once intended it as a joke.
He presented it to him the night before he went away on a job. They might run missions together more often than not, but they still have their own things going on. This is going to be long term, at a time Jason can't afford to leave Gotham for an unpredictable amount of time. He still spent every free moment he had during the last week making plan after plan for every possible contingency Slade might encounter, trying to make sure he's got his six covered even while he's not there to watch it himself.
And the night before leaving Jason gave him a collar. Thin, unadorned except for the clasp and ring, and the same color as his undershirt, easy to conceal under his gorget. The leash he bought is much less subtle, strong and sturdy, with my love embroidered in Jason's flowing cursive, because he's an unrelentingly earnest sappy bastard even while he's making a point.
He wears the collar for the entire duration of the job, knowing that Jason's love is coiled within the inside pocket of his partner's jacket, as effective in making him think twice about the risks he's taking as if Jason was here, ready to yank him back with it.
He now gets why Jason liked wearing his.
He buys a leash himself as soon as he's back, and it becomes a whole other thing. Or the same thing again, only now on steroids.
It's both a fun game and a thing they take seriously, a joke and love and everything in between.
Jason sneaks up on Slade in their living room, clipping his leash to Slade's collar and proclaiming he gets to call the shots for the night, and they have a fantastic time of it.
Slade sees Jason worrying himself into a raw nerve, and he decides to take over, the clink of the silver chain settling like comfort over Jason's tired shoulders.
They keep each other from doing stupid shit, they offer each other support, they take responsibility for each other's actions when it's necessary.
And they horrify and bewilder the general populace with how they've chosen to show affection, which is always a plus.