Chris Brown Deletes Twitter Account after Feud

R&B singer Chris Brown has deleted his Twitter account after a vulgar online exchange with comedian Jenny Johnson.

Johnson says she's now receiving death threats on Twitter from Brown's supporters.

The fight started when 23-year-old Brown posted a picture of himself, saying he looked old. Johnson replied: "I know! Being a worthless piece of (expletive) can really age a person."

Brown fired back with a series of crude sexual jokes. Johnson posted a link to a news story about Brown's 2009 assault on singer Rihanna.

Before deleting his account, Brown wrote: "Just ask Rihanna if she mad??????" The on-again-off-again couple has been seen together recently.

A representative for Brown's record label didn't immediately respond Monday to an email seeking comment.

Brown had 11.6 million followers on Twitter.