sounds like breeding behaivior. The male will aggressivly keep all other males and even other females away from his girlfriend when courting. Dont be suprised if you have a holding female very soon.
Around the female the male will:
Very colorful male(if the fish is orange he will be bright orange etc..)
Very fast shimmying,
Very fast shaking,
Overall appears very hyper very aggressive and obsessed with one particular female fish.
Flares his fins up around a female and "poses" directly in front of her like : hey look at me ..
flares and shakes at the female darts off returns seconds later to shake at her again.
(Both fish )Slow circling over a flat rock or sand.
To other males the male will:
Attack any fish that comes close (male or other female)
Break off spawning behavior to chase away a male then return to female
Over all be highly aggressive running around like a chicken with its head cut off (no offense to any chicken lovers lol)
A holding female will often go off by herself, sometimes at the top of a crowded tank, and look like she has a mouth full of food, she will not eat food. but other wise appear normal.
Those are the breeding signs I have seen in my fish.
CG