Nycindie, I will DEFINITELY check out that article. I just don't really have the time to read right now, but I wanted to reply to ya.
I think you are right. In either case, I have decided to wait to tell him. Whenever him and I are hanging out alone together again and it feels right to do so, I'll find a way to let him know that the boundaries of the relationship with my fiance have changed.. Letting him know that we are now okay with pursuing romantic relationships outside of each other. This will give him some time to digest it (I won't be hitting him with a double whammy - my relationship with fiance has changed, oh AND I'm in love with you.. Lol.) In addition, like my fiance pointed out, I might find that he actually comes to me with any feelings he might have after awhile, once I've made it known it would be okay to do so.
In either case, I'm sure I will tell him eventually, but it's not like I have to admit I've had the feelings forever. He's probably not even gonna ask. All that matters is my feelings at the time of me telling him.
And in the meantime, I'll do what you said! Enjoy the changing of things now... And the truth is, the main thing I want to change between fwb and I, is that we spend more time together... Him moving in will prolly lead to that! Lol.
Thanks again all