if a guy really liked you he wouldn't care what size your boobs are. i'm really petite 5'2" but i have 34C size breasts and seriously, they're huge. i honestly don't like them much. i often wished i had smaller breasts like lower B cup sizes. my butt apparently though is very small which i hate. but my boyfriend still loves every portion of me. i used to worry that he'd only pay attention to my boobs but he doesn't.
don't worry about it too much. guys that only date girls for their breasts are imature perverted humans