I read a fic a while ago. And I remember kagome had photographs of inuyasha cheating on her with kikyo. And she takes them to sesshomaru and they go out dancing to make inuyasha jealous. And wind up mating. Their memories combine I think and sesshomaru learns that kagome is some sort of team leader for a special ops team or something like that. And he also is an agent. But they didn't know.

I've been looking for it but can't remember what its called or what categories I had found it under.

The story you're looking for is sugar0o's Do you know how to dance?

It is rated MA, still incomplete, and currently has 10 chapters.

Here's the link:
www.dokuga.com/fanfiction/story/156/1?author=226

Happy readings~!

Thank you!!