[James98]

A man's perspective here. Men know breast size is a sensitive subject for women. Any boyfriend or husband will tell you that he likes your breasts just the size they are for fear of getting a response "so you don't like me because my breasts are too big/small?" Never ask him directly about your breast size but you can say "I think I can and want to increase my breast size, is that ok with you?" 

The fact that he is willing to massage your breasts is a bonus and you should encourage him to do that with oil (coconut, almond, or aloe vera) and possibly with some added fenugreek.