Joe Jonas swamped by girls at birthday pool party

The singer turns 22 today, Monday, and got his party on wearing just his swim shorts at the Liquid Pool Lounge on Saturday, much to the delight of his admirers.

'Female fans surrounded the area, trying to get a glimpse of [Joe] in his bathing suit,' a source told People.

His group then moved on to the Bellagio Hotel, where they enjoyed a meal at Yellowtail Japanese Restaurant & Lounge, followed by a game of blackjack at Deuce Lounge.

'Joe was swarmed by nearly 20 female fans dying to get an autograph or photo with [him],' an insider said. 'After signing a few autographs and meeting with fans, Joe finally made it to Haze Nightclub, where he rocked the crowd with a special live set, performing tracks off of his debut solo album FastLife.'

Speaking at the event, Jonas told People: 'It's a coming-of-age record. I want to present it to people my age – a little bit older.'

He then retreated to the VIP area, where he was spotted chatting with a bevy of beautiful girls.

'Girls were pushing to get near him,' another source said. 'He was definitely loving the attention.'