Große Mädchen weinen nicht (2002)

Kati and Steffi are best friends since childhood. But as they step into adulthood, both their perfect friendship and their personalities get harshly tested by a series of unfortunate events; mainly caused by Steffi finding out her father wasn't quite faithful to her mother, and the two girls getting hit by the consequences of her delirious revenge plans. When things get out of hand, the two girls find themselves in the middle of a mess, and Kati starts questioning whether or not Steffi is really so precious to her. Where will Steffi's plans of penalizing her father's "evil" lover will end up..? Will the girls' friendship be saved..?