So several years ago read this fic, where Arthur and Merlin are best friends, but Arthur is with Gwen? At Merlin's opening exhibition, Arthur kisses him. Eventually, Gwen/Arthur are married. Pining, LOTS of angst - mostly I just remember the vague kissing scene which was insanely hot (to me at least). Any idea? I realize I am not describing this well at all, I just hope someone remembers something.
Graphite Rain by Allganne