I know that this will be hard because you are in love, but you should honor your loyalty to your friend above all.  If your friend is generous, you may still be able to keep your love relatiohship as well.

Does your friend love this man from a distance or is he calling her everyday pretending that he is in love with her?  I can't tell from your letter.  If he is leading her on, HE needs to tell your friend that things are over.  You should a) comfort your friend b) stop seeing your man and c) wait until she gives you permission before you start seeing him again.  If the guy has any integrity at all, he will wait for you.

Integrity? Come on, he is a GUY.

However, you might want to think carefully about dating someone who acts like that, because he may do it to you some day.

On the other hand, if she is in love with this guy and he has not done anything to string her along, it's going to be up to you to tell her what's happening.  Tell her as soon as possible and be there to comfort her.

Yes, she needs to be more honest with her friend.

Since it's gone on so long, she may be most hurt by the fact that you didn't tell her than by the fact that you have been seeing him.  Ask her what will make her most comfortable -- for example, does she want you not to mention the guy for a while?  Ask for her forgiveness.

To most people, my solution is going to seem extreme.  But think back on the friends you've had -- I have some from when I was born.  They are there for you every time you break up with the person that seemed so important one month earlier.