A scheme Donut and Katia worked out together, hidden from Carl and Bautista until it was too late to stop.
In the last quiet moment before the assault, Donut tells Carl there is something she should probably mention now that it's too late for him to do anything about it. She and Katia have a plan, worked out together, assuming they get through this next part.
Two conditions come attached: Carl can't tell Bautista, who is going to be mad, and Katia told Donut not to tell Carl at all because he will Carl it up. Carl's outraged repetition of the phrase is cut short — the rest of the conversation gives way to the Donut's Secret Benefactor Box confession and then Li Na's go order.
A secret scheme deliberately timed so Carl can't interfere.