The mysterious force that acts on large groups of females when they pose for a photo. While never strong enough to affect anyone in the background, or any male ever, it is strong enough to cause a slight buckling of the legs of photographed women.
Sarah strapped her knee before going to her hens' night, as her physio had warned her of the danger of girl gravity.
by Scott Timms October 29, 2012
Get the Girl Gravitymug.