Powder Blue and Brown Mating dance.

[blue eggs]

I have had a powder brown tang for about 4 years in my 180. Decided to try a Powder blue also. I removed the brown for a couple days to let the blue settle in then I introduce the brown back to the tank. The Powder blue chased the brown for the first day and the second aggression went way down. Now I have notice them occasionally swimming in circles in what looks like a mating dance? They are not biting or attacking each other now.

Thanks