Okay, so I remember this fic was actually a oneshot first, in a collection of various oneshots. I don't remember if they were all SessKag but they were a collection haha. Later, the author wrote a full story out for the oneshot. The oneshot was about Kagome being a perfume maker and she had come to Sango's and Miroku's for dinner at the same time as Sesshoumaru, someone she had not met before. She, finding out that he was a youkai, decided to ask him to help her with scents by having him sniff her neck.
Ring any bells?