Mischa Barton is furious with boyfriend Cisco Adler after a nude picture of him emerged on the internet.The revealing picture of Whitestarr singer Cisco surfaced last month on website ParisExposed.com, and the former 'The O.C.' star is livid. A source told Us Weekly magazine: "They had a blow-up. She was furious."Cisco - who refers to the situation as "Ballgate" - told the New York Observer newspaper: "Mischa wasn't too excited, to say the least."I think it was actually worse for her than for me in some ways. So yeah,I'm going to try to keep my pants on from now on."Paris' shit got stolen, and somehow she had a picture of me naked in there.That's Paris Hilton for you."I think it's pretty rock 'n' roll. If it was taken yesterday I would've freaked out, but then I looked at the picture and I was like, 'Oh, that's from 2001. Whatever!' "Despite rumors that 21-year-old Mischa has dumped Cisco, 28, over the picture, his representative insists they are still together. A representative for Contango Records said: "They are fine - very happy together."