How should I defend my girlfriend..I think my guy friends are jealous of her and me together...?

I am a shy college guy who never ever thought I would have a girlfriend..it turns out, I got the smart, goodlooking girl most guys wnat,but couldn't get..many tried..I did not go after her..she came after me and I ran from her for a long time before going out with her.....but, my guys friends make rude comments about her...they say such things as, her jeans are so tight she must have to use pliers to pull them...how do you ever get in her pants? They call well done lower back tattoo a bulls eye or a tramp stamp, and the call her cigarettes ***** sticks, but I have no idea why..she smokes the feminine Virginia Slim 120's, the long ones...so why the ***** stick comment...I have shielded her from most of these comments, but she has heard a couple of them once or twice....I really love her, she is not just fit and good looking, but a very good student, better than most I see..so, what should I do..I don't want to stop seeing her...I think she is y and smart