Fell in love with my friend, What do I do?

Stay friends, let him decide. If he is happy with her, then let them be. It is hard, but that is the best thing to do. It is better to stay friends, then loosing them over a break up. Its a good thinking that you saw the inside him, not many women see that. Just the outside. I will say, tell him how you feel. Just tell him, do not act on it. If you are open, then he will know. He might say that he feels the same, but he is in love with his girlfriend. Just tell him that you accept that. Do not date him, unless he breaks up with her. That will be worse, if he is dating two people.

honey, I know where you're coming from! not a fun place to be in hey =(
I'd say that if he's happy with his current girlfriend (sorry, it says 4 months ago so I don't know how current this is) then maybe you should just leave them be.as hard as it is.
and it depends on whether you want to try to get over him or to try and 'get' him.some people say the best way to get over someone is to tell them how you feel.
hope this helped & it works out.