Is it normal to ask your girlfriend to get bigger breast

I am man 22 years old, i have girlfriend 22 years old too, she got beautiful boobs and I love it when we do sex, but her boobs is small a Little and I prefer the bigger boobs.
She always say to me if i liked everything in her body after we doing sex.
Is it normal to say to her that I love your boobs bigger and if she can make her boobs bigger.
because from the past I was watching the boobs of playboy models and I become (can't live without boobs like it).