Firstly, I would like to give three specil names.
There are three people in it, girl A, girl B and boy C.
They three are good friends. At first, boy C liked girl B. Girl B refused him. Girl A knew all the feelings between girl B and boy C.
later, girl B found she was sort of liked boy B. but boy C liked girl A alreadly. And girl A has became boy C's girl friend.
In order not to hurt girl B. they didn't tell girl B the true relationship between girl A and boy C.
This secret