it's cause she messed around knows she made a mistake, and is trying to get back in your life.
shes probably playing games cause she wants to make sure you really want her. if you ignore her she probably will try harder. (but what do i know)
problem is if she messed around once, she is obviously capable of doing it again.
do B. then A. then C.
if she still comes back
do D. bang her, kick her out of the bed and make her feel like a used piece of shit