Girls, how can i get over being embarrased about my girlfriend?

I am dating my first girlfreind ever...i am so shy that i never thought i would even have a girlfriend, but i have met one...i am in my second year of college....i am very conservative, and she is quite the opposite..my family has bet her once, and they want her to come home with me this weekend...problem is they are conservative and she is teh type who likes to dress very y...the really tight low jeans, tight tops that ride up and show her lower back tattoo...and, she is a cigarette smoker...and none of us are...they have met her once and my mom seems to like her...they know about her tattoo and they have seen her smoke cigarettes...she only smokes outside.., but, I get embarrased and red faced about the tattoo and relly embared when she smokes a cigarette...I love her and I think she is y as hell, but I am afraid they will think I am turned on by "that kind of girl"....I am but i don;t want them to think it...what can i do to get over this...she is a pack a day smoker, so she can;t go long without smoking...and she always wears really tight jeans, puls her tat shous when she mover or bends...I don;t wnat her to think I am ashamed of her...help please