archer not showing up at all in the household because he already knows about the squabbling between reader and Rin both before and after the confession is so funnily canon
(F:S/N) Archer having to deal with Rin and tsundere!Reader
I loved this idea too much so now we have a Part 2, focusing on our poor boy having to deal with this.
Part 1 Here
If there was on image to be used that could perfectly represent what happened with Archer every single time Rin and (Y/N) was in a room, it'd be this:
Archer's preferred place to be whenever they would arrive would be: LITERALLY ANYWHERE ELSE.
Being a Servant, he can't in good conscience leave Rin completely alone, especially during the Holy Grail War.
Even outside of one, there was never a 100% guarantee that she'd be safe, meaning he had to be around in some capacity.
Plus, there's the fact that he could hear Rin's thoughts even when miles away.
(Rin) "Ugh! (Y/N) is so thick-headed, just like Shirou and Saber! They have no idea how to properly serve good tea! You agree, right Archer?"
(Archer) Yes, I agree. Just like the last five times you complained about this...
He was currently out in about in town just to get away from the Tohsaka manor, but even then that was no respite. At least it was some small comfort that he couldn't hear both parties...Most of the time.
He doesn't necessarily hate (Y/N) and Rin's relationship. If anything, he finds it to be kind of sweet, in a way.
When they're being honest with each other, that being only like 5% of the time before they became an actual couple.
...At the same time, it's also entertaining to rile them up and hurl them at the nearest group available to deal with it.
...
When Rin got up to use the bathroom before dinner, (Y/N) clicked their tongue, crossing their arms and turning to her servant.
(Y/N) "Ugh, I can't believe you have to deal with Rin as your Master!"
(Archer) "She isn't the easiest to get along with, a fact that you no doubt already know. But if that's the case, why do you cling to her side like a lost puppy?"
(Y/N) "Excuse me?!"
With a shit-eating grin, he simply shrugs at (Y/N).
(Archer) "If you hate her so much, the door is right over there."
(Y/N) "I-I don't hate her, I never said that!"
Then without hesitation or mercy, he directs his gaze to Shirou and Saber, who were sitting at the table across from them.
(Archer) "Really? Could've sworn Shirou mentioned that observation to me."
(Shirou) "You son of a-...!"
(Y/N) "You need to mind your own damn business, Shirou!"
Meanwhile, Saber just glared daggers at Archer, whose amused expression remained unchanged.
...
Once they finally became a couple, Archer surprisingly becomes protective over the both of them. Rin for obvious reasons, but he knew she'd be devastated if anything ever happened to (Y/N).
But outside of life and death situations, he wasn't exactly surprised.
Getting to hear his Master's thoughts, Archer knew exactly how she felt about them, for better and worse.
Which made things SUPER awkward when they were spending time together in the Manor, having to find SOME way to occupy himself so they could be affectionate in peace.
Though this doesn't stop him from popping in and reducing the two of them to stuttering messes, something that thankfully never ceases to be hilarious.
...
(Rin) "Come on, let me help you up already! Quit being stubborn-"
(Y/N) "H-Hey! I said I can walk on my own. You...don't have to worry about it."
(Rin) sigh "Fine. But if your foot twists again, I'm not helping since you insist!"
(Archer) "Actually, she was just telling me to help you out in case you showed signs of falling-."
Which was technically a lie, but he knew she'd be thinking about it a few minutes later. Still, didn't make her reaction any less visceral-
(Rin) "A-ARCHER!"
Meanwhile, (Y/N) could only blush at that, making Rin sputter even more as his grin grew.
...
Needless to say, he's happy for Rin and (Y/N).
...Mostly so they could stop trying to side step their feelings every goddamn interaction, seriously that was annoying to watch.
[ID: Rin Tohsaka and Archer's sprites from Fate/stay night posited next to each other. They are both smirking smugly with their right fist perched on their hip. End ID]
perusing through stay night's sprites for a thingamabob I wanna draw and I giggled when I saw these two. me and the bestieeee