Lindsay Lohan says she has been with girlfriend Samantha Ronson for "a very long time."

The Mean Girls actress - who was first seen with 31-year-old Samantha late last year - has so far refused to speak about her personal life but finally confirmed the pair are in a happy relationship.

When U.S. radio show host Ted Stryker asked: "You guys, you and Samantha, have been going out for how long now? Like two years, one year, five months, two months?"

Lindsay replied, "For a very long time!"

Lindsay, 22, also spoke about the horrific plane crash in South Carolina last week, which killed four people and left former Blink 182 drummer Travis Barker and DJ AM with second and third degree burns.

She added: "Samantha and I woke up to emails about the crash. We were both really scared. AM has been a great friend to me and he's such a good guy and Travis a great guy as well and an amazing father."

"It was all really scary."