I started writing and didn't finish a chat bot one time that meats the criteria. (Actually 2 chat bots)
The formula is this: 1) The 2 bots have a scripted conversation. 2) When a human tries to participate (read: interrupts) they have a conversation like "Bot1: who is this guy? Do you know him? Bot2: NO". Then they happily continue their chat completely ignoring the human unless he types their username. Then it goes "What do you want?" and "Could you please stop highlighting me" etc
The formula is this: 1) The 2 bots have a scripted conversation. 2) When a human tries to participate (read: interrupts) they have a conversation like "Bot1: who is this guy? Do you know him? Bot2: NO". Then they happily continue their chat completely ignoring the human unless he types their username. Then it goes "What do you want?" and "Could you please stop highlighting me" etc