Impossible my friend. For anybody to have a full house there must be at least one pair on the board. You have already said you had pocket Kings and hit one on the flop. This means for the other guy to have a full house you must have the same. Kings over whatever pair is showing on the board.
So i put it to you...that you were pished and didn't realise what hand you had.
Remember once I was playing a game of poker at my mates flat and I've just won a massive hand and have loads of the chips, so I nip to the toilet totally pished and decide to give myself a pep talk in the mirror in the bog, "Come on Gaffa, keep it cool and play sensibly from here on", I said to myself....
Very next hand I get delt x2 kings and another comes in on the flop so I go "all in" and end up losing the lot!