The MC should be able to say "no, we won't ban the other parties, and if you mention that again, I'll have you executed". "Sorry, sir. I recommend you ban the other parties..." "GUARDS!... Now I am off to Iori, bye" :D
I am a terrible negotiator, but that wasn't hard at all. They didn't even have real problems. Though I take my bisexuality like Woody Allen said: twice as many chances :D and I laugh at narrow-mindedness.