Why do guys like my skinny friends?

Im 14 .Really tall ( 5'9) and weigh around 160 pounds , but im really curvy . ( c boobs , bigger hips and butt) Im pretty proportioned with my measurments ( 38 - 34 - 40) . and to top it all off i look like im 20. Most of the time older guys (20-40) hit on me and i cant walk donw the street with out getting second looks or hoots and hollars. its flattering i must admit but it seems that my skinny size 0 -4 friends are getting all the relationships. They assure me that im pretty and that crap , but iwant to know why the hell am i always single?