Odd Coral Beauty behavior

[Arsenix2001]

I introduced a month long quarantined coral beauty to my 40 gallon reef yesterday. Today I noticed my watchman goby and purple firefish seem a little off. Hiding in different areas. Not witnessing any aggression but tonight just now something odd. The angel was behind the rockwork and rubbed himself all over the purple firefish who was hiding in the rocks. Almost like a fish that presents itself to a cleaner shrimp. My fireshrimp was near by but not doing any cleaning. Any thoughts?

 

[Nigel35]

Could be a show of dominance very interesting.