Rihanna has admitted that she has some hang-ups about her body.

The singer is no stranger to showing off her flesh in photoshoots and Instagram selfies, but it seems she isn't 100% happy with how she looks.

Speaking to E!, the 'Stay' star said that she actually would like a bigger backside.

Rihanna said: "I do pick on my body. It's a thing that women do. We walk in front of the mirror and we look at our butt. Is it getting bigger today? Ew, it's still flat."

The singer meanwhile won the Best Urban Contemporary Album Grammy Award recently for her effort 'Unapologetic' and she has admitted that it came as a surprise.

The Bajan beauty said: "I was so shocked. Really, I was at home and one of my friends hit me and said, 'You've just won a Grammy', and I was like, 'What?' and when I went on the Internet I just saw 'Unapologetic'. It was quite an emotional moment surprisingly. But I was in shock, I'm excited, it was a good feeling to still be that excited at this point in my career."