The Mortal Instruments star Lilly Collins refuses to join Twitter because she fears opening herself up to audiences will spoil their enjoyment of her films.

The 24-year-old actress explained that she logged on to the social networking site for a brief time but decided to close her account so fans would concentrate on her performances and not her personal life.

Speaking to Flaunt magazine, Lilly said: "I think there is something great about seeing someone as a character because you don't know them that well as themselves.

"I like to be able to watch movies and not know too much about someone personally. I don't want to be tainted by thinking, 'Oh my god, they had the best pasta last week.'"

The Mortal Instruments: City of Bones is in cinemas now. Read our review here