What Are My Clown Killis Doing?

So on Sunday I got 2 Clown killis and some more Pygmy Cories.
They're both in QT right now and today they just keep on sticking together swimming side by side.

I'm pretty sure my killis are both male because of the tail. What are they DOING?

I'm so confused right now

*So sometimes, they stop doing this behavior and go back to normal. Is this typical behavior?

 

They are fighting. They swim side by side and push water at each other, to guage who will be the alpha (the stronger push). They both look male, and will never be friends. Male only tanks always get competitive. They shouldn't harm each other though.

 

Mine do that too. The one in my picture is the alpha male. He always stays in this same spot and the other tries to steal it (it is right under the food hole)

 

Sounds like a flash dance or something. Showing off at each other and whose the most macho buddy in the tank.

 

Thanks for the input everybody, but they should be fine in the long run right?