|Robert Pattinson at the 'Cosmopolis' premiere in NYC'|
The 26-year-old actor - whose girlfriend Kristen Stewart admitted to an affair with Rupert Sanders last month - appeared to have put his recent problems behind him when he arrived at the PH-D Rooftop Lounge at Manhattan's Dream Downtown hotel at around 10 pm, with onlookers describing him as "relaxed and comfortable" at the bash, despite the attention he attracted.
A source told People: "He was very charismatic, all smiles, looking very relaxed and hugging all who stopped by to say hi. The general crowd gravitated towards his table, but he was shielded by security. He was surrounded by women and the movie's cast.
"The whole room was watching him, and he looked genuinely at ease and comfortable the whole time."
The evening capped off the first time Robert has appeared in public since the news of Kristen's affair broke, walking the red carpet at the New York movie premiere having earlier taped an episode of 'The Daily Show'.
At the 'Cosmopolis' screening, the 'Twilight Saga' star admitted he felt "absolute terror" about getting close to his fans following his personal problems.
He said: "I felt fear, absolute terror. It's great - I didn't expect it from the first 'Twilight' movie, I never expected my life to be like this and so it's kind of weird to have lasted. And for people to come to movies that I'm really like proud of and I didn't really think anyone's going to see, I mean it's like, it's kind of amazing."