WHY PAULA WON'T DANCE ON "DANCE"

TALK ABOUT DIRTY DANCING! “So You Think You Can Dance” producer/ judge NIGEL LYTHGOE keeps Tweeting fans that he’s personally invited PAULA ABDUL – an “American Idol” judge during his reign as that show’s producer – to appear on highly rated “SYTYCD” as a guest judge…but here’s what My Spy says to that: “Liar, liar, pants on fire!”

According to my in-the-know bro’: “Not only has Nigel never contacted Paula’s people about doing the show – he’s never asked her personally.” So…why not?

Said the source: “Nigel knows full well that Paula despises him. They fought constantly when they worked together on ‘Idol.’ It was like a battlefield, with the two of them always fighting over creative decisions like dialogue between SIMON COWELL and Paula. Nigel had Paula singing the blues on ‘Idol’ – so she’s definitely not up for any dirty dancing.”