Puffer pairing, mistaken identity??

[Davoaldo]

I've recently added a PJ cardinal to my tank. For some reason my valentini puffer and PJ cardinal are displaying some weird behavior.
The puffer will swim toward the cardinal then turn sidewards with the belly facing the cardinal. Then the cardinal do a little peck at it and the puffer don't seem to mind. They also swim together all the time. Both fish are very young only about an inch to inch 1/2.

Whats the nature and purpose of this behavior? Is it just a coincidence?

 

[Davoaldo]

bump can anyone help me?

 

[McTeague]

The cardinal is displaying submissive behavior to avoid being eaten. He will eventually be eaten though.

 

[Davoaldo]

oh dear.....
I thought it was the other way around, like the clown males will turn belly so female will stop attack.

I am trying to bring the puffer up with other fish so that it won't attack them when he gets big. Looks like its not going to work.