For once, the joke’s off Britney

Britney Spears is out, Posh Spice is in -- as a comical reference in a lyric sung by the Lady in the Lake in the musical “Monty Python’s Spamalot.”

Asked why the lyric was changed in the song “Diva’s Lament,” “Spamalot” author Eric Idle said Tuesday in an e-mail: “Because we don’t laugh at sad people. Mike Nichols [the director] requested it, and he’s right. We changed the lyrics in London, on tour, on Broadway and in Las Vegas. We think that it’s now too sad. Britney Spears is being tortured to death, and we don’t want to be on that side.”

The change was made in the various companies last week.