Stretch marks

I'm usually very embarrassed of my stretch marks and I'm only 17. Every time we have innercourse my boyfriend loves them but I don't. I can never wear anything that shows my stomach because of my stretch marks and I can never wear shirts without sleeves that shows my arms because of my stretch marks. I wear black because it makes me look skinnier. Part of the reason why I don't like showing my body it's because one time they told me how do I have stretch marks but never had a baby. It made me feel really bad about my body. So I just want to ask if anyone knows how to get rid of them. I'll really appreciate it!