“Chris Brown Beat You Because You’re Not Pretty Enough”: Amanda Bynes Slams Rihanna On Twitter

Despite being arrested and taken in for psychiatric assessment and then accusing the cops of lies and sexual harrassment, Amanda Bynes hasn't given up her Twitter habit.

The teen star took to the social media machine to tell Rihanna what she really thought of her, TMZ reports.

It didn't take too many words either...

She followed the tweet up with another insult, about wanting to name her dog Rihanna.

Pic: TMZ

The moral of the story? Don't mess with RiRi. She will ALWAYS have the last word.

Amanda then responded (but subsequently deleted):

"@rihanna unlike ur fugly faced self I don't do drugs! U need the intervention dog! I met ur ugly face in person! U aren't pretty u know it!"

Phew, Bynes, back up... you'll only get burned.