bounce for the ounce 

a reference to the ratio of breast size to overall body weight.
a girl thats slightly overweight but has nice luscious breasts is more appealing than a slim flatchested girl because she has more bounce for the ounce. (in the case of guys who value larger breasts.)

Yeh, she could maybe shed a couple, but you gotta admit, shes got plenty of bounce for the ounce.

bounce for the ounce by Monkey January 24, 2005