Chris Brown has deleted his Twitter account after a shocking combat with comedian Jenny Johnson. When Chris Tweeted a picture of himself with the message 'I look old as f*ck! I'm only 23..' Jenny hit back straight away. She Tweeted in response: I know! 'Being a worthless piece of shit can really age a person.' The conversation then dismounted into abuse on both sides, with Chris Tweeting unrepeatable insults to Jenny, who has more than 300,000 followers. At one point, Chris Tweeted: 'Just ask Rihanna if she mad??????' Chris has struggled to shake off a negative public image since he attacked Rihanna at the Grammys in 2009, although she seems to have forgiven him. source online..