Rihanna's boyfriend keeps her "sane".

The 'Russian Roulette' singer - who has been dating baseball star Matt Kemp since the beginning of this year - admits spending time with the sportsman helps calm the stresses of her hectic lifestyle.

She explained: "I have a boyfriend. I'm so happy. I feel really comfortable, and it's so easy. I have such a chaotic life, but at the end of the day, that is just my peace. It keeps me sane, really, talking to him and talking to my family."

The 22-year-old star also spoke of her "confusion" in the aftermath of being assaulted by then-boyfriend Chris Brown in February 2009 because she couldn't understand why her "best friend" would turn on her.

She added to America's Elle magazine: "A year ago, I was very confused. Because he was my best friend. All of a sudden, one night changed our whole lives-not only our friendship, but our lives. I wanted to wake up one day and just not have that pain anymore. I wanted to be with him again or get over him-it was either-or. I just didn't want to feel the pain, the confusion."