Rambodian
No I'm not cambodian
I don't see why this is even up for debate.
Yes, he's single however, she is married end of story, your friend should realise and accept that, forget about her and look eleswhere.
Wise words Darkoz.
Bella, you need to tell your friend to back off, she is a married woman and is obviously in a marriage that is having trouble (whether her husband knows/is responsible for or not). Your friend is taking advantage of this situation for his own personal needs, this is wrong and may lead this woman to do something regrettable to her marriage. It may well be the deciding factor that breaks the marriage down? who knows, is that good or bad? it doesn't matter. It is not for your friend to decide, if he is a man he will tell her to get divorced before anything can be taken further, a clean slate must be made before any more physical or emotional contact can be made.
For your friends sake, ask him if he wants someone who is committed to him, or unsure of what they want. Is there children involved.........I would simply say to him that to become a home wrecker is to be a low life.