Gay guys dont turn straight.Call it personal experience.And if he ever does anything with vidya sexually then its ll be the work of alcohol and loneliness.It would be a one time thing.But can stretch the story as it ll give vidya hope or she might get pregnant(Drama world!).And Garuv ll either end up leaving karan(or karan leaving him) or getting shot or going in a coma or something tragic.That could be realistic as many gay guys here hardly can run away.And coming out of the closet has got like 10% chance here.
If u ask a gay guy.I would say if Garuv doesnt do anything soon,karan ll leave him.If I was karan I would try my best to take him away.But if can't then I ll leave him and move on.