For the fan of the separation between a woman's breasts, it is also revered to the separation between her butt cheeks. Often revealed by a low cut dress or low cut undies.
This social group is for spinners and those that love them. The Online Slang Dictionary defines a spinner as "[a] women so small and light you can literally spin her around while she is on top of you during sex".
Don't get me wrong, I love all boobs, but there is just something about big knockers that makes you go MMMM! If you think more than a handful is a waste, then this isn't your place...