I love an even fight and, as you know, twins are as even as they get. Luck and desire rule when two carbon copies battle. Being twin sisters no two females can be closer in love and competition. Having grown up together they don't have the normal inhabitations and are more likely to keep battling even when clothes are lost and more likely to attack any part of the others bodies that they can get a hold of. As vampires they would end up locked together in a tight catball. Feet locked as legs are wrapped around legs. Arms wrapped around their siblings backs as they dig nails deep into the others back and pull hair. Mirror breasts pressed together as they feel the others heavy breathing as their firm bellies press together. These two would feel the others hip bones press together. They would intertwine so tightly they might end up only being able to bite one another.