Of course breast size affect a woman confidence. I had girlfriends with very big boobs very proud and not shy to show them in vertiginous cleavages, as they said to show women to not try anything with me cause I already have the best woman. When I went to parties with them only big titted woman flirt with me in front of her, the flat chested ones didn´t try a thing when my busty girlfriend was around, only when I was alone or with friends they came, almost all the time to criticize my girlfriend (she dress like a whore, she wears push up, I´d never wear those clothes,etc)