The basic premise if I recall correctly is that it's a modern AU sort of thing where everyone knows one another prior to the story starting. It's definitely an adult/MA fic that I either read on Dokuga or Spark before.
Anyway the gist is that Rin thinks she's in love with Sesshomaru but he isn't paying her attention so she gets some incense or something to use to get Sesshomaru to love her back, and Jaken sets it up for her, but it works on SessKag instead and she leaves upset with Hojo at the end who goes off on Sesshomaru for "hurting" Rin by sleeping with Kagome instead. SessKag get together; I think InuKik might already be there, too. When Jaken uses the incense/smut dust/whatever it is, it impacts Sesshomaru's ability to act on his true feelings, and he acts on it for Kagome.
I think they were all staying the night or weekend at a lodge or something. Kagome might have just come back from school or from overseas, I'm not sure. I could be wrong.
Any help in finding it again would be greatly appreciated!!