Disappearing Act (Su): A street performer can use performance to divert attention from an ally. All creatures within 30 feet that fail a Will save (DC 10 + 1/2 the bard’s level + the bard’s Cha modifier) treat one creature chosen by the bard as if it were invisible. This performance affects one additional creature at 5th level and every 6 levels thereafter. If the targets take any action that would cause them to become visible, they become visible to everyone. The bard cannot use this ability on himself. This ability is a mind-affecting effect that requires visual components.
So how does this work? If you invis an ally and they break it do you have to start all over again, or does maintaining it re-invis them? Do the enemies need to make saves every round?
Seems like you could answer this simply by reasoning it out.
Bard use ability.
Friend or friends 'disappear".
One or more of them do something that draws attention to themselves and breaks Indivisibility.
They need to do something that causes them to vanish again.
Either they need to provide their own invisibility, or satisfy the conditions under which the Disappearing Act requires to work.
Does the bard have to STOP what he is doing and start over? No I imagine not. He's always been trying to draw attention away from his allies anyway. His allies don't auto-disappear though, they still have to beat those will saves to re-enter the Disappearing Act.
Seems like this would be most useful in crowds with mixed hostiles and non hostiles. In a situation with just enemies, and the Bard and his allies. all he is really doing is making himself the target of every enemy in sight who fails the Will Save. Damn good way to die.