I am tall, fat, AND pear-shaped, so there was no way I was going to escape getting them!
I remember when I first started getting my stretch marks I was still in high school.

I was active and slender, but got them anyway. I got huge ones all over my lower abdomen, and smaller ones on my upper thighs, upper arms, hips, and breasts. At first they were bright purple, they hurt because I could feel the skin tearing as they formed, and they caused me no end of anguish. (Thanks, family genetics.

)
Over time they faded into a silvery-pink shade, and now I hardly even notice them anymore. That's not because they've gone away or are less noticeable when I've lost weight, but it's because I'm so used to them that they are just part of me. Sort of like I don't "see" my freckles anymore unless I think about it and
look.
But, if it makes you feel better, check the link below. It shows that
no one, not even super-skinny celebs, is immune to stretch marks!
http://photos.tmz.com/galleries/stretch_marks