This is horrible.

So, this will be long. 
I haven't been hanging out with my group of friends recently as one of the boys just came out as being gay (which I have no problem with), but he had been seeing my friend (female) for months before coming out to anyone. So things had been a little awkward around our group because of this. 
Just tonight I found out that he has started seeing a guy he works with, and when he told everyone we were all really happy for him and celebrating, the guy is a few years older. Later on he said in passing conversation that this guy he's been seeing is actually ENGAGED and he doesn't know whether he wants to come out or not. (Him and my friend have been sleeping together). 
I am seriously so disgusted that he would do this, and pretty much do not want to see him again, considering he knows this guy is engaged and is still sleeping with him. 
Half of me wants to find out who his fiancé is, and tell the girl, or force my friend to tell the guy he's seeing to tell her, but the other half of me doesn't ever want to talk about it again. 
I think my friend and the guy he's sleeping with are both in the wrong. 
Just wanted to rant. Sorry.