jinalyn

I think it is more of the guy's fault because his reason for not talking to ur friend is shallow.I mean, they are close friends but then he chose to kinda ended it by not talking to the girl anymore just because the girl didn't tell him what's her sickness is. They,being close friends, do not mean that he has to know evertyhing about the girl,of course,there would be secret sharing but there are things that he sometimes need to understand and just let it be as a secret,a bit of respect for privacy is also needed or if he really wants to know then maybe he could wait after some time when the girl is already prepared to tell about what happened.
Also,the guy expected the girl to tell him what happened coz they are close friends so i think it hurt him or made him feel unimportant when the girl refused to tell.
But if the girl has that "trust" to her close friend,that trust is enough to be her reason to tell what happened or maybe she is not really prepared to tell for now.

About u,being pushed to take sides,i dont think it would be good to choose between them but if u really have to ,then i guess u should be at ur friend's side not to the guy's side since it is the girl who is ur friend.
Being on her side doesn't mean that u need to ignore that guy too..
You could just clear up her mind and give advice about it ,listen to her,and see what you could do.