Two of the world's most glamorous women admit they sometimes feel down about their looks. Though confident and self-assured in public, both Posh Spice and J Lo can feel insecure, admits the US actress. Jennifer Lopez made the shocking revelation when asked to describe what she thought was the sexiest thing about a woman. Describing Posh as a "beautiful, successful woman" the actress provided an insight into their friendship. "I was just talking about this with Victoria Beckham," Lopez, 38, reveals in the latest issue of US magazine Glamour. "Victoria said: 'People would never guess you're insecure. Are you? Because I know I am'. It was like she had to hear it from me. And I said: 'Yeah, of course I am'.She said: 'But you seem so confident'. And I said: 'Because I am confident. It doesn't mean I don't have my moments. But you have to remember the value of your individuality - that you have something special and different to offer that nobody else can'. "Victoria said: 'Oh. I love hearing this. What you're saying is so great!'. "It was really sweet." Acknowledging that this conversation would shock many, Lopez said: "That's why I wanted to put it out there: Here you have a beautiful, successful woman who does her own imaging and branding and has a great family and kids - yet, at times, she feels very insecure about herself. "We all do."