I'm sorry i've never been in your situation. Love is never easy. How long have you all been together? Does his wife suspect anything is going on? Does he still love her? Are there children involved? I'm sorry for all of the questions I am just trying to get the whole picture.

If you all have been together for a long time and he still hasn't left his wife...Odds are that he isn't going too and he is going to just keep you on the side. Please don't let him. You deserve better. You should not live your life in the shadow of his wife.

In a relationship you should not feel alone. I understand that you love him but sometimes love just isn't enough. If you haven't already...You should really talk to him and ask him about future plans and tell him that you don't want to be the bit on the side. I don't want to tell you just to leave because that isn't my place...But in my opinion I think that you should leave.

Also another little rule of thumb...Usually if they will cheat with you...They will cheat on you.

I hope that you can leave this situation and move on and find someone that will be with you and *only* you.

Actually I am in the same situation you are in. Only to make things worse the person i'm involved with doesn't live in the same place that I do. We met on-line and have been communicating for over 2 years. I did meet this person some time back and we got on wonderfully together. This is really the person that I want. This person has also made mention of the fact that they couldn't believe how well we got along. I know there is nothing between this person and their spouse. Yet do to other reasons they remain together. It has been a rollercoaster ride. I do love this person very much. One thing that a friend of mine has said to me is when and if i'm ready to end it I will know. I don't judge you in the least.
I wish you the best of luck with it. If you want to pm me please feel free.
We could probably support each other!