Credit: KC Bailey/FX

Louis C.K. has returned to the stage for the first time since admitting last year to engaging in sexual misconduct.

The comic made a surprise appearance Sunday night at the Comedy Cellar in New York City, one of his favorite stand-up haunts from the past. He took the stage around 11 p.m. ET for a 15-minute set but did not address or mention the allegations, according to The New York Times.

“It sounded just like he was trying to work out some new material, almost like any time of the last 10 years he would come in at the beginning of a new act,” the Cellar’s owner Noam Dworman told the Times.

Dworman, who did not watch the show himself, said that he was told C.K. “was very relaxed” and received an ovation from the audience before he began his set.

In a New York Times article published in November, four female comedians claimed that C.K. had masturbated in front of them, while a fifth claimed he masturbated while speaking with her on the phone. C.K. responded with a lengthy statement in which he admitted that “these stories are true.”

He added, “The hardest regret to live with is what you’ve done to hurt someone else. And I can hardly wrap my head around the scope of hurt I brought on them … I have spent my long and lucky career talking and saying anything I want. I will now step back and take a long time to listen.”