What do you term this kind of person?

Some random thought... #justsaying #nopunintended

Once upon a time, person A, B and C were friends.

So one fine day, B was unhappy with C and complained to A about it. A even told her not to blow up the (small) matter as all were friends for so long despite being unhappy with C too since long time ago.

However, the matter was being blown up. A got involved, for no reason.

A started hating C as C sent her friends to insult & curse A and family.

Subsequently, B bitched to A about C and vice versa.

After some time, the issue died down, A is no longer friend with C and couldn't be bothered about C at all.

Then...

B AND C RECONCILED. And at the same time, B fell out with A.

This time round, A got attacked.

B then bitched to C about what A bitched to B (about C) before. (How nice!)

Thank god for the strong character that lies in A, A wasn't affected much at all.

- The End -

So, what kind of person is B?