Aggressive Picasso female

I have a pair of picasso perks that I have had for about 4 months. Over the last week and half I noticed the female is getting real aggressive. Is this normal with perks?  These are the only perks I  have.

Here is a video of them. But soon as I record the good girl comes out. The female is about 3 inches and the male is about 2.5 inches. http://youtu.be/9SqVXVzanqQ

I have one set of docile spawning picasso pair(they have never bitten me or each other). I also have one VERY aggresive picasso, that will not tolerate his tank mate, unless the tank mate is in top 1/4 of the tank.

These two always stayed together until recently. They have never spawned yet that I know of.

Is it an established pair for sure?  You said you only had them 4 months.
 
I also had mature spawning picassos, and for some reason out of the blue, he female became aggressive toward the male.  I tried a few things, but eventually the male died from getting beaten up and stressed so much.  I have since then paired another $15 beautiful male picasso to the female and they started spawning within 6 weeks. I didn't even knew if the new one was still a male or not when I tried to pair them.  Got real lucky.  
 
I considered that maybe the female started doubting the virility of the male, or decided he wasn't a good mate or wasn't protecting her or the eggs well enough.  Maybe she was testing him or perhaps she just wanted a new mate.  If you see him getting scared or fins torn I would separate them and let them look at each other through a box for a while.  If she continues to pick on him, it might be best to separate them completely.

So far there are no torn fins. I did a big water change and that's when the aggressive behavior started. Do you think she could be ready to spawn and he isn't.