Britney reveals first time she kissed Justin

Britney Spears says she first kissed Justin Timberlake during a game of truth or dare.

She says she was 12 at the time and Justin's friend dared her to kiss him.

Britney was speaking to Oprah Winfrey while promoting her new film Crossroads.

She also revealed she stays in shape by doing 50 sit-ups a day.