Powerman2000 has two panels up featuring Zambi, a girl with enormous breasts who grows even bigger every time she drinks milk. The panel at right is the "after", but she ain't exactly small in the "before", either.

Anyway, it's a great example of the "uncontrollable" urge school of breast expansion, where even when a woman is aware of the consequences of further breast growth, she just can't help herself. She wants it. She wants to be bigger and the drawbacks of having boobs the size of beanbag chairs are beneath consideration.