Charlotte said:-
.... my breasts are definitely sensitive - and react to stimulus. (There is like there is an electrical current that flows between my breasts and my pussy - hard to explain...)
A number of years ago I stumbled across a strange outcome when using needles in play. Quite unconsciously I was inserting needles in certain places on the body which had the happy result of causing sexual excitement.
Then I came upon an article on the subject of 'milk lines', an invisible line from the armpit, through the breast and nipple area, to the pubic region.
Apparently there is a stage in fetal life, about 6 weeks gestation, when the fetus has two rows of nipples along those 'milk lines', which, in the human fetus disappear as gestation continues, though some may develop third or more (supernumerary) nipples, often later in life.
Since discovering milk lines I have been of the opinion that in many people these lines, though invisible, are extra sensitive and I have concentrated on them, often with pleasing results. I have no proof of this of course and any study of the phenomenon has been relatively unscientific.
Have a look at this page and the diagrams. Form your own opinion. http://en.wikipedia.org/wiki/Milk_line
Have a look also at http://en.wikipedia.org/wiki/Nipple which has the following suggestion, though it does not link to 'milk lines'.
The nipple and areola of males and females can be erotic receptors, sometimes intense enough to elicit an orgasm in some women. Research has suggested the sensations are genital orgasms caused by nipple stimulation, and may also be directly linked to"the genital area of the brain".
In women, sensation from the nipples travels to the same part of the brain as sensations from the vagina, clitoris and cervix. Nipple stimulation may trigger uterine contractions, which then produce a sensation in the genital area of the brain.