It's probably also important to mention that decolletage is not actually the skin which forms the cleavage in particular. It's the skin from the neck down to the cleavage really. When you buy a night cream for your decolletage (yes you can get them) you don't put it on your breasts. It goes on your neck and chest area above your breasts.
So, it's not as localised as the gents here might think.
