The 'Twilight' hunk went along to trendy nightspot The Garage in Highbury and Islington with a big group of pals to support his friend Bobby Long - who was performing an acoustic set at the venue - but upset many female fans by refusing to pose for photographs with them.
One female reveller said: "He was shielded by his friends, but Rob leaned against the bar pint in hand. He was looking his usual yummily dishevelled self - black leather jacket, skinny jeans and smouldering good looks - and most of the women in the room suddenly felt the need for another drink. A few were even brave enough to ask for photos, which he seemed to be mostly refusing."
When the 23-year-old actor - who is dating his 'Twilight' co-star Kristen Stewart - began to get frustrated with all the unwanted attention, he and his friends tried to hide in the bar's outside area.
The source added to Radar Online: "He dodged into the smoking area and was quickly surrounded by a wall of friends but just hung out with them, no one really bothered him and he just chatted away with people."
However, Robert quickly started to grow bored of the cold and returned to the bar for another pint of beer - though he continued to maintain a low-profile.
The fan said: "Considering that the music was so upbeat, he was there with friends and had a couple of beers, I was surprised Rob wasn't enjoying the music like everyone else. Instead, with no one bothering him, he just went back to his corner of the bar and hunched over another pint with his head down."