Justin Bieber

Justin Bieber looked silly and immature while he performed a dance atop the bar in a Boston discotheque.

The pop star performed in New England city this weekend, as part of his ‘Believe’ concert tour.

Bieber could not resist showing off his famous moves, got atop the bar, where his tour disc jockey DJ Tay James was booked to spin a set, and started dancing.

Apparently the 19-year-old star took off his shirt as soon as hopped down from the bar. He then started 'grinding up on' several ladies and many didn't appreciate his flirtatious caper.

'It's not the kind of place where you'd do that,' the source noted. 'He looked ridiculous.'