y would kids join a sexual club anyway, This club should be baned from kids under 13years or so, Wht do u guys think?

Fanpop is actually banned for kids under 13 , they just lie about their age.
And secondly I don't see anything wrong with them here , we don't post porn here.Here they can actually learn about sex.

Like Drisina said, kids under 13 aren't supposed to be on Fanpop at all.

This spot is for education. Not porn, or to find partners, or to have raunchy disscussions. Young teens can have questions and concerns about sex, just like everyone else. Why shouldn't they be allowed here?

As everyone has already said, fanpop is a site for 13 year olds and over. Also it is the parent's responsibility to police their children's and/or young teens internet usage. They should not be left to browse the net on their own. At the very least they should have web filtering software on their computer.

hiding sex from kids with raging hormones just makes the kids look for the sex that bit harder

As long as they read the banner and take it seriously, they should be ok.

I think, you're right

It depends on how mature they are honestly,one kid
might abuse this knowledge when another kid might
use it constructively. So it depends.

It depends on how mature those kids are, most of them don't even know about sex and I don't think it's right for them to join the spot.