Okay, okay, here me out: a fake dating fic where the monster of the week is only going after married couples, right? But instead of just pretending to be married, they actually... go get married. Like Dean just goes "well I guess this is the only way to lure this sucker out" and they grab a couple of fake IDs (since Dean is legally dead and Cas was never actually born) and they go elope. For the case.
Sam is off with Eileen at this point (either on a date or a hunt of their own idk) so he's not there to point out how glaringly unnecessary the whole thing is. He just gets back to the bunker to find the marriage license on the kitchen table, and just about has a heart attack. Like, he's known that Dean and Cas were into each other for a long time now, but he hadn't had a clue that they were dating! And now they're married?! And Sam wasn't even invited???
He's so shocked and annoyed that he doesn't even know what to say. He just tracks down Dean and slams the papers down in front of him with a "What the hell, Dean?!" Then he has to stand there and listen as Dean explains the whole thing, and Sam can't quite figure out if his brother is lying to him, or if he's just that much of an idiot.
Turns out it's the latter.
And the thing is, Dean and Cas both just act like it's no big deal. Like marrying each other is a completely sane choice to make. They don't get awkward about it, or act in any way like they regret it. If anything, they only get more idiotic and flirty. Like Dean just will not stop bringing it up in conversation. He's constantly making jokes, and calling Cas his husband. It's ridiculous.
Sam tries to bring it up to him once. About how maybe Dean and Cas were both using this case as an excuse to indulge in something that they didn't think they were actually allowed to have under normal circumstances. But he hedges around it a bit, trying to make the blow a little less sharp. And that fails miserably when Dean purposefully decides that Sam is talking about marriage in general, instead of specifically saying that Dean wants to be in a committed relationship with Cas. Dean goes into a big rant about how they were never gonna get that whole 'settling down with 2.5 kids' apple pie life. And then ends it with making a joke about how, hey, he got to marry his best friend though, at least. "That's the dream, right?" And then walks off before Sam can respond or start tearing his own hair out.
And then when the case is over, Dean and Cas are just like... why bother getting a divorce? What's the point in that? It's just a lot of hassle and money for no reason, right?
So they just... stay married. And by this point, Sam is banging his head against a wall.
