Humorous, tongue-in-cheek reference to Philadelphia's proximity to, ease of travel to and fro, and cultural influence on/by New York City.
Q: Where do you live, Brooklyn?
A: No, I live in the Sixth Borough and am just up here for the night.
A slang term for the Southeast Florida metropolitan region (Miami, Ft. Lauderdale, and the Palm Beaches). Often used more narrowly to refer to Broward County, wherein Ft. Lauderdale resides.
He says he's from Brooklyn, but he grew up in the sixth borough.