Mischa Barton is on the verge of splitting from boyfriend Cisco Adler because of his possessive behaviour.The couple, who were reported to have got engaged last November, had a blazing row on New Year's Eve after rocker Cisco became jealous of Mischa spending too much time with her friends.Cisco's band, Whitestarr, had played at Miami's exclusive Victor Hotel that night and after the concert 'The OC' beauty invited a host of male friends to join the couple for a party, sparking a jealous argument between the pair.A source is quoted by America's New York Post newspaper as saying: "Cisco was very angry that Mischa wanted to hang out with some of her other friends, and not exclusively with him."There was a lot of slamming doors, stomping around and swearing at their bungalow at the hotel."The pair recently denied they had got engaged after reports claimed Cisco proposed in Hawaii in November.The 26-year-old musician - who was once engaged to Rod Stewart's daughter Kimberly - said: "Yes, Mischa is my girlfriend. But we are not engaged."
Mischa, 19, started dating Cisco in August last year, two months after she ended her one-year relationship with oil heir Brandon Davis.