Paranormal Romance & Urban Fantasy discussion

I am in search of a book that has a leading man that may be a demigod that may have been a sex slave in his youth. The sperm of the demigod was used as a rejuvenating cream? There are tunnels, involuntary sex rituals (of sort)that require an additional penis. This guy hates sex though because of his past and is very unhappy about the sex he must have because it is out of his control. The women who have to endur the sex are given something to help them make it through the sex (i guess).There is a lady who has never met the leading man but recognizes him because she has seen him in her dreams. These two are soulmates I suppose and end up stuck in these tunnels together with another individual (male) who also grows 2nd penis for this "ritual" and they both mate with her. All of these clues are vague and based soley on the description I was given by my M.I.L who does not rembember title of book or its author. Please help me find this mystery book. Someone suggested the book Nicholas from the series Lords of Satyr and though it seems very close, some elements of my description seem to be missing (though i have not in fact read the book, and could very well be the book I am looking for.lol)