I wanted to read this but I though first I should read In a blue moon, but I can't seem to find it. Where is it at?

I absolutely loved In a Blue Moon and Footsteps. They were both really good and really angsty (my fave combo)!

What I don't understand is why Inuyasha finds InuTaisho and Sess' past relationship so sick. I mean, father and son? Well, they're brothers so it's still an incestuous relationship. Maybe it was explained in the other story? It's been a while since I read it