It’s not that kind of party, Hugh.

As Hugh Grant introduced a drive-in screening of HBO’s psychological thriller series “The Undoing” this past weekend out East, he welcomed the crowd of heavyweights by saying: “Hello, Hamptons. I think you’re going to watch two episodes in your cars, which is … really weird. Maybe you’ll do some necking, or some dogging … whatever people do in cars in the Hamptons.”

His co-star Nicole Kidman was left blushing, while we wonder whether attendees at the Cinema Society screening even understood the British slang (which means to have sex with strangers in cars in secluded places).

Guests at Jill Rappaport’s Last Buck Ranch included David Burtka, Christie Brinkley, Lorraine Bracco, Jennifer Esposito, Bobby Flay, Nancy McCartney, Candace Bushnell, Joanna Coles, Rosanna Scotto, Steve and Christine Schwarzman, as well as Grant’s brother Jamie, who also got a shout-out in the intro. Following the showing, there was a long “honking” (as in car horn) ovation.