I was on board as well. I thought the whole thing was hilarious, especially as the chap in question repeatedly asked the poor member of cabin crew to announce that he was doing this over the tannoy.
It was diffused superbly with "I doubt everybody on board is in such a party mood!".

Wish I could have finally met you properly Mr Prospero though. Don't suppose you're travelling back up on the 1486 tonight?