A single large nipple in the middle of the chest area, can lactate only under serious stimulation and smells like mangos on close aromatic inspection. Often mistaken for a third nipple.
Dick: Cor, check her tits outs!!
Harry: Fuck her tits, check her tittipeeny out!!
Bill: Haha you've got a third nipple.
Ben: Its not a third nipple, its a tittipeeny.