1980s Gaelic fantasy book Wolf King?

I remember reading a fantasy book steeped in Gaelic mythology called the Wolf King from the 1980s or early 1990s. I remember the sidhe being talked about a lot, they may have been the villains, but I honestly don't remember the plot. There was something about these dangerous green mists you weren't supposed to go into. And I remember it was really horny. But there are so many modern horny books with Wolf King in the title, I cannot seem to find this one and I don't remember the author. As far as I know it was a two book series, I had both but I don't remember the name of the second one. Please help!