Are my friend jealous of my girlfriend and me?

I am dating a girl that almost all guys want...tall thin y brunette..although I know most of my guy friends find her hot...they always point out what's wrong with her, but always check her out...they claim her jeans are so tight that they look painted on, they call her lower back tattoo a tramp stamp, and she smokes cigarettes, even though I don't, so they say the only reason i am with her is that "girls who smoke cigarettes poke" How do I repond to this...She is y and they know it..honestly I do not believe i deserve a girl this good, so how should I handle them..they embarr me