Tiger Oscar Behaviour Question

Hello. So in Nov. I got a baby "albino" oscar, named him Newton. He's not actually albino but anyway... So, he(I'm assuming) is SIGNIFICANTLY smaller than my other oscar Thor(named before I saw her lay eggs), in general they hang out together, eat together, and alls well. But periodically my large oscar will chase my little one around biting him. Which brings me to my question, is there any way to know if my large oscar is just asserting herself? Will she stop when the other oscar gets breeding size? When I had two oscars before, they were both adults and they jumped right into the liplocking and nest making. So this is new for me, thanks for any advice. Here's a few bad pictures of Newton, but you can get an idea of his size.

Better pictures. You can see the rip in his tail from the biting and chasing.

The only damage to him is the tail rip, there's never been serious injuries and the big one doesn't try very hard to bite the smaller one. Just a quick dash and a nip really. After thinking about it, I figured if the big oscar really didn't like the small one, there'd be WAY more damage to his body than just a rip in his tail.