Twitter Fight: Joan Rivers Makes Chris Brown Joke, Rihanna Responds

Joan made a domestic abuse joke at Rihanna's expense and called her an "idiot" yesterday afternoon. You'd better believe the singer insulted her right back, like she so often does.

Rihanna first replied with the following tweet, which has since been deleted:

And later, with this:

But we all knew Rih wasn't REALLY done with her fight...