How about ::she cheated on him with his twin brother and said it was an accident. His brother confessed and she was pissed at him. So she killed his brother. They went to court and she won; neither losing anything. She went back and tried to patch things up with him but when she went to his house she knocked over the case filled with his brothers ashes. 2 months go by and she asks if thing are cool and he says no so she goes into a depressed state and blames it on him. He gets beat up by her(protective, buff, great jaw line) older brother because he (being guy in blue) made her sad. 3 years later they are there texting.
Just me...
Hmmm, I'll go with "science went too far..."