[Milan'22]

I have 2 percula Clowns, both a bit over 2" with one slightly larger.
I've had them for about 2 and half weeks and during this time they never bothered/bothered by anyone. One seemed to be more dominant, and would swim all around the tank, while the other would move around less, but they looked fine and ate well.
Recently, though, the larger one seems to be tackling the smaller one which is now losing colour (becoming grayish) and its fins are becoming frayed. This mostly happens during feed, one time he even appears to bite the side fin. At other times the smaller will float close to the glass by itself, and the othe will come up to it and they both appear to be vibrating. The smaller one looked pretty bad so I brought it to the lfs where we asked if it was a parasite and what we should do. A few people disagreed and said one is establishing its dominance and they could be mating.
This seems logical but the smaller clown looks pretty bad, and the larger is only getting more agressive.
What do you think?

ps if you want, i could post a pic.