Demi and selena VS Miley and Mandy!ok i hav a coupk?

ok i like luv miley and all but y woulod she make fun of Demi's gap! and if she isn't mad at selena then y on the miley and mandy show they made fun of them? is it that on JB's recent youtube vid Demi was on it and miley has never been on JB's youtbe and that they reffered to demi and selena as they're close friends AND that Demi is dating cody linley?