This just came to me from out of nowhere. I know this was a great story, but I can't remember all that much about it, just this one scene: Kagome is staying with a man in the modern era. I'm pretty sure he is a human. I don't know if she is his friend or girlfriend. I believe his girlfriend. He has a big poster of an anime girl above his bed. Sess comes over, and the guy tells Sess he fantasizes about having that girls lips wrapped around him. I think the guy could be a computer geek. They are in danger, and the guy (and his friends?) works with Sess to fight whoever their enemy is. It gets pretty action-packed. It's definitely a Sess/Kag, and I read it quite a while ago, so it's not new. Any ideas???

I think you might be referring to Madman by Rinseternalsoul.

Kagome doesn't live with a human guy but she is good friends with a guy named Rishou in the fic and he is obsessed with anime. And there is a scene where he talks to Sess about the fantasies he has about the anime girl he has posted over his bed. And there is definitely tons and tons of action in the story.

http://dokuga.com/spark/story/4227/1

I hope this helps! ^_^

Oh, yeah! That's the one, for sure! Thanks so much!