Those headcanons with the bros are just yes!!! But now I need go know how everyone reacted when Error first got drunk?? Like imagine him being the only one drunk in a rolm with Reaper and Ink,, I can imagine so many hilarious situations from that omg,,, *realisation* holy shit imagine Error drunk in Nightmare’s castlehellthing with everyone being like "what the fuck?" Maybe I’m insane because in my timezone it is the early hours of the morning, but I find that thought VERY funny xD
Oh man XD (No worries with the time differences! It's just now morning for me lol)
It really depends on the kind of mood he's in when he starts drinking. Generally, I see the brothers as affectionate, dorky drunks separately, though with a past like Geno has, there must have been times where he cried himself to sleep right? Eh? What do you think @jellyfish-swims-through-gold ? :3
Now following this thought process, would Nightmare tolerate such painful genuine affection near him? And how early into Error's first stay at the castle are we talking? Did he get into Nightmare's booze or did Nightmare sneak these drinks into him? (But I digress :3)
But yes~ headcanons for the first time the others saw Error drunk (assuming the other is sober or buzzed/tipsy and not yet drunk):
Nightmare thought the drinks would make Error angrier. He's got so much rage within him that nudging it just a little with the liquid should be enough to destroy more worlds right? So why the hell is he clinging and asking what his boss' favorite color is?!
Cross stared in slack-jawed disbelief and fumbled for his sketchbook. It was a rare opportunity to try and sketch Error so close especially... well, Cross' inspiration had claimed with a flushed face and booze on the breath that it was too hot. Peeling off the layers of clothing, he whined, "I'm sleepin' here," before collapsing in the nude on Cross' bed. Later, Cross would remember his manners and cover Error up to rest.
Horror had challenged Error to a drinking contest. Having never seen the destroyer relax and let loose, he thought it'd be a fun time. And it was! For Error. Who had a long conversation with Horror about how snakes had a neck, a body and a tail, but it all looked like a head and tail from the outside. Horror stopped serving him drinks after that.
Killer has never seen Error drunk. Just heard the rumors.
Ink's first rime seeing Error drunk was after a bad moment with Nightmare and the castle. Error wanted to use the protector to forget his problems for the night and go back to being enemies. And was both surprised and pissed when, after drinking some pink, Ink said no. Error wouldn't know if Ink remembered that, and Ink never explained why he initially denied him after years of interest, but Error is glad he did.
Spright and Geno experienced drunk Error at the same time. It was a gradual thing, with the stoic destroyer scowling fiercely and taking each shot given to him, but with eaach shot, that scowl lessened, and the tension faded from his back. Soon enough, he was lounging over the others then demanding that they three go dance. Puns escaped him more than the destroyer would ever admit to. Spright and Geno remember being sad about this. He must be hiding so much as a nightmare...
Reaper saw Error drunk at the after party of one of their weddings, clinging tightly to Ink and leaning into him to try and disguise his state of inebriation. When the god talked to him, mentioning work and a pun, Error easily responded with inappropriate death puns for himself before growing unusually quiet and refusing to speak.
The closest Dream has ever gotten to experiencing a drunk Error was through stories told by Ink, until that one time in book one where things went south and the AU was on fire.
This is great thank you for your ask!