What caused my J brand jeans to start ripping?

I'm so upset because my favorite j brand jeans ( a href="http://www.tobi.com/product/10212-j-brand-12-lowrise-pencil-leg-jeans-912-in-ink-denim?cmp=fgl" rel="nofollow"http://www.tobi.com/product/10212-j-bran…/a ) are ripping around the seams at the inside of the knees. They have these white faded lines and at one part there is a little hole forming. Is this because they were too tight at the knees?? i don't get it, because celebs wear them really tight too but they don't have white lines on them. I also know I bought the right size because when I tried on a size bigger, they were huge at the waist. Help!! I don't want to buy another J brands and have the same thing happen, since they cost $158!!