All three percs are fine now. The new addition is the smallest and he fought the male for awhile but now they all are swimming peacefully. the male and the new guy both do the submissive dance.
I noticed mine doing that today to! My clowns wern't paired when I got them, and the larger somtimes nipped at the smaller one. Today when feeding them the larger nipped at the smaller and the smaller started vibrating for a secound! Does this mean the're pairing up?