Hmm, i agree its a hard one. My DD will also be 13 this year and IMHO, if she was invited to a party where boys were sleeping over - she wouldnt be. I agree with Krysalyss, the boys could be sent home after the party. I know its hard with the trust thing - and of course they think they know everything - but this is something i'd put my foot down to. I remember me at that age and well, i worry about my DD!!!! And really, do you think the boys (& girls) will stay in their "rooms" once you've gone to bed??!! My other worry would be if the other kids are telling their parents that boys are also sleeping over.

Good luck with it all anyway!