Tales of a Liar, Pervert, and Nobody

This has been bothering me for some time, now, and I've mulled it over in my mind how to approach exposing this idiot, and finally come to the conclusion that this is probably the best approach.  Now, before I continue, let it be known that I don't hold any prejudices against those with alternate lifestyles or different religions, but this one person in particular just sets my hackles on edge, and makes me want to vomit, scream, etc. 
The person in question is a (very) openly gay "leader" of a particular group in the local area.  I had my doubts about him from the moment I met him, but being the "fair" person that I am, I gave him the benefit of the doubt for the first few months I knew him, and then his true colors started to glare out of nowhere. First of all, he started to make subtle, and some not-so-subtle advances at me, all of which were politely declined by me, at first, and then quite firmly discouraged. In the time that I thought we were friends, this person "confided" in me about things that really made me think twice about his motives.  Apparently, at one point, he had a younger friend (a young boy) that used to spend weekends at his trashy dump of a trailer, whom he quite openly encouraged to run around his trailer and property in his underwear and in the nude. His tales never went beyond that, but his comments about the young boy's body, etc really made me wonder. I got really uncomfortable with these stories and finally told the guy that I didn't want to hear anymore.  That was just one of his true colors that began to show through.
Another thing was that this guy calls himself a "leader" and a "teacher", but there were times where he would "teach" about something of which I already had knowledge, and his information was so far off the mark that it wouldn't hit the broad side of a barn, to coin a phrase.  When confronted about this, he flat out told me "I'm the teacher, you're the student. It is not for you to question me." (Say what?  I was taught very early on that questioning leads to learning.) But, then again, what else can you say about someone whose chosen "name" has nothing to do with Fairies, as he thinks it does, but is more synonymous with both a certain Shakespearean fool and an ass.
The final straw was when I agreed to help said person with a few projects last year, and each time, when I volunteered my time, he never asked me to do anything (he outright ORDERED me around like I was some mindless slave) nor was he very appreciative of any of it.  I had at one point come up with a very good idea, and suggested that it be implemented, and instead of thanking me for it, he turned around and presented it as his OWN idea. That was it for me, and I confronted him about it, and quite calmly told him how I felt about him stealing credit for something that I had totally worked on without his help or input.  At that point, he threw a temper tantrum and called a "tribunal", lied to everyone else in the group and held a vote to have me removed from the group, without a warning.  What he didn't take into account was the fact that Kat would not choose his little group over me, and she told me about it. I presented my side of the story, all the while being threatened by his mindless sheep of students, to the point where I just turned and walked away. I let things cool down, but never trusted anyone in the group, least of all him, after that, and finally Kat and I made the ultimate decision to leave.  We made our intentions clear to everyone in the group one night, and stated that our paths were leading us elsewhere (neither of us was learning or getting any "enrichment" at that point in time), and left under the assumption that we were leaving on good terms, and were even told by Mister Asshead that we would be welcome back at anytime.
That was the last we'd heard from him until recently, when certain ideas that we had had for the up and coming event we're going to (that unfortunately, the ass and a couple of his toadies will also be attending) suddenly were nixed and re-presented as "his ideas". I very politely confronted him about this, and received a infantile rant as to how he would not take orders from me (I just stated that I didn't appreciate his actions), and proceeded to call me any number of names.  That was the end. I vowed that I would no longer deal with his assinine and infantile manner, and if I see him (which is almost inevitable) when we take our trip, I will not acknowledge him, and will let it be known that he will be welcome nowhere near our camping area.  He is dead to me.