Diamond goby threat display?

[davidcalgary29]

The only fish in my Evo is this goby -- now that my orchid dottyback has disappeared (possibly into the goby). Whenever I come near the tank, the goby comes out of its burrow and settles into the front of the tank to watch me. It then opens its mouth, slowly, and flares it a few times. Is this a threat display? A greeting? I haven't seen this with another fish before.

 

[DinoMagnet]

The only fish in my Evo is this goby now that my orchid dottyback has disappeared (possibly into the goby). Whenever I come near the tank, the goby comes out of its burrow and settles into the front of the tank to watch me. It then opens its mouth, slowly, and flares it a few times. Is this a threat display? A greeting? I haven't seen this with another fish before.

To me I believe it’s a threat, my Diamond does that to my coral beauty during feeding time. Then my beauty backs it’s rear towards him all while fanning it’s tail at the goby lol

 

[KWT]

All 3 of my gobies do that, and we have stare downs. They usually slide sideways after a bit like they are tired of me and could care less I am there. I like them a lot.