I'm 16 and slim, and I've been told I have an "amazing" body by many...
BUT I have stretch marks on my breasts, hips, thighs and the back of my knees.
They're not too bad [fading due to use of an INCREDIBLE, yet very expensive product], but definitely noticeable, and with summer around the corner I'm kind of worried about what my boyfriend will think, as I'm not sure if he's noticed them yet.
I don't think guys would care. I have stretch marks and I ask my guy friends all the time and they said it's really not that big of a deal. I really hope you're guy thinks the same way because you didn't ASK for stretch marks!