Page Six sex scandal?

[tenaya]

In The Mentalist tonight, they used the phrase "page six sex scandal." Last night on Castle, the police woman that is flirting with Castle told him something like, "I don't live my person life on Page Six." Castle is supposed to be in NYC, while The Mentalist is in California. I live is California but I don't know what this Page Six refers to. I'd appreciate any clues to help figure it out.

Thanks!