Let's get the basics out of the way first. 'Chair fic' is this legendary (and I mean LEGENDARY) Dan and Phil fic from like, 2014 Tumblr peak. The actual title is 'Asking for a Friend' by sporkss. The core plot is hilariously simple but executed with this slow-burn, agonizing pining that defined an era. Dan, a university student, finds this abandoned wooden chair on the street and drags it back to his and Phil's shared flat because he thinks it has 'character'. Phil thinks it's hideous and possibly haunted.
The entire story revolves around this stupid chair as a proxy for their entire relationship. They bicker about it, have deep conversations next to it, and the chair just... sits there, witnessing all their unresolved tension. The climax isn't a kiss, it's Dan trying to secretly get rid of the chair after a fight, and Phil freaking out because the chair's absence makes their flat feel wrong—it's not about the chair anymore, it's about the domestic space they've built together, crap furniture and all. The resolution is them buying a new, mutual chair, which is basically a marriage metaphor. It's a masterclass in using a mundane object to explore intimacy.
What makes it iconic isn't the plot points, but the vibe. It's the epitome of the 'uni flat share' AU where the biggest conflict is IKEA furniture and the softest confession happens over takeaway. I re-read it last year and it still has this weirdly comforting, specific early-2010s atmosphere that you just don't get anymore.