Help! My wife is killing me

[PoonTang]

.... said the little black clownfish living in my Biocube.
I dont really understand it, they were doing just fine then the larger one starts picking on the smaller one. They are juviniles and I thought ,OK they are just sorting out who is going to be the pant wearer in the house. I was about to separate them it was getting so bad and then the Male went MIA...that was about 3 days ago. Fish can be so cruel.