Lady GaGa will make a guest appearance in Gossip Girl, Penn Badgely has revealed.

Badgely's confirmation came as the singer was pictured leaving the set of the hit teen series in New York yesterday.

Lady GaGa tried to keep a low profile as she was bustled out of the Ansche Chesed Synagogue in the Lower East Side by security.

Lady GaGa leaves the set of Gossip Girl in New York yesterday.

Hlary Duff and Jessica Szhor were also spotted near the location yesterday.

After letting slip about Lady GaGa's cameo, Badgley also confirmed rumours that the third series of Gossip Girl will feature a steamy threesome.

"Yeah, she's a part of the threesome — I'm kidding," Badgley, who plays Dan Humphrey, told MTV.

"She's not, but there is a threesome and there is Lady Gaga, so you gotta keep watching."

The current series has already featured a guest appearance from Sonic Youth.

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