i dunno how old you two are, but geeze...
guys like boobs. Some have specific tastes and preferences. But just because you like burgers doesn't mean you hate chicken biscuits.
Confidence and honesty overpowers pretty much everything. Porn is porn, but if he would date some empty headed chick (both in brains and in heart) just cause she had huge boobs, then what he loves are meat sacks and not people. That makes him a man-child, and you can treat him that way from now on.
Yes, I like big woobly boobs myself, but not to where'd I'd put up with a mental dwarf in a relationship. Nor does it mean a b-cup would be unwelcome, especially on a confident and honest girl.