Just tell them of your sexuality from the beginning, it's always best to be open with your partner. If they can't accept it, then they never deserved you. c:
I used to be so self conscious about my breasts, they took until I was 19 to get to a decent size. I now like them, but I'm not very happy with my areola size... they're huge!
I'm bisexual though so I know the size doesn't actually matter, I know in my stories I write about DD's but any size is nice. Smaller boobs are more sensitive so being with girls with smaller breasts can be just as sexy as they get so wet just my playing with their boobs whilst busty girls aren't as sensitive c: