Help needed with Endlers

[Fishtacos]

I have 2 adult Endlers in my tank, the yellow one always seems to be chasing the blue one. It is always solely focused on it, even if i put my hand in between them..the yellow 1 will go around my hand and focus on the blue one and chase it. The yellow one will constantly chase it and then the blue one turns to one side and does a shaking motion. This has gone on for months for some reason. There are plenty of females in the tank but the yellow endler does not care. It happens 24 hours a day, are they just playing or is the yellow one showing aggression?

 

[emeraldking]

The yellow one (yellow saddleback is the correct name) is just showing dominance to the tuxedo endler (black flame is the commercial name). As long as the yellow saddleback will chase him but not fight, they should be okay. But maybe some hiding spots would be preferable for the tuxedo one. Both males are from a known hybrid strain.