what to do?girl afraid of marriage and men.?

As she's been his girlfriend for three years, she doesn't sound so distrustful of males. Your friend has a choice: either to accept the current arrangement or insist that he must marry. I imagine that the former option will not provide him with long-term happiness, so he has to insist on the latter. Nevertheless, it takes two to marry, and if she is uninterested in that (and unwilling to seek help with her alleged emotional trauma), then he must accept that the relationship has no future. That being the case he shut cut his losses, finish with his girlfriend, retain just the happy memories of their past together, and seek out a more suitable woman. He would not be to blame for the collapse of the relationship. Many people suffer some bad experiences in life - but the point is to handle that in a positive way, and not let it adversely affect your present day dealings with others. Someone trapped in an emotional inner turmoil, and not prepared to be released from it, is not a suitable person with whom to have a relationship. That person is not only self-destructive, but ultimately, s/he will bring you down also, and your mental health will be affected.