Still a very complex situation..?

Ok, I've been friends with this couple for about 3 years and since day 1 there has been an unspoken attraction between me and the woman.. so now 3 years later they have a kid and she's unhappy and tells me about all the mean and controlling things he's done so i comforted her and gradually we became closer.. she said she was ready to leave him about 2 months ago and kicked him out of their apartment.. but never solidified it, leaving in his mind a chance to get back together..at this time her and I began to a very intense relationship of our own and was really good and positive until about a week ago when she said she was feeling like a tramp and needed space and time to figure things out. she says she loves me but is afraid to tell him because they have a child together and a long history.. this whole thing goes against my character and am having a hard time with the guilt and unknown factors of the situation. i want to just tell him and get it over with and get some resolve. but..