Quoted By:
Because they played it for laughs instewad of playing it straight.
Same reason they had Misty ask if it was Bianca or Latias that kissed Ash at the end of Pokémon Heroes, to allow the inocent (and the easily-outraged) to imagine it was the human as "pokémon wouldn't do that", despite making it quite clear during the film Bianca had no interest whatsoever in Ash. Bury your non-standard relationships indeed.
