We think some Beliebers may have to change their pants after this. Justin Bieber flashed the crowd at a recent London concert. Did they get a glimpse of Jerry?!

Of course not! Biebs is a class act, after all. But his Beliebers did get a good look at something else: his abs! Bieber performed his massive hit 'Boyfriend' at the Capital FM Summertime Ball on Saturday (June 9). He impressed with his choreography and vocals, but he's clearly been putting in as much work at the gym as he has in the studio.

Rocking jeans, fingerless gloves and a Union Jack tank with matching vest (swaggy!), Bieber teased the crowd. At the conclusion of the track, he took off his vest, crossed his arms and stared into the audience, who shrieked so loud you'd think all the glass in the room would shatter. Perhaps inspired by the appreciation they showed, Bieber grinned from ear to ear as the music stopped.

Then just as the next song began, Biebs smiled some more and gradually inched his flag-printed tank up, then in one fell swoop, showed off the goods before sprinting backstage. Ow ow! Someone's been doing sit ups. Check out the videos below to hear the boy wonder perform some oldies and new gems live at the Wembley Stadium in London. That Selena Gomez is a lucky gal!

Watch Justin Bieber Flash His Abs at the Capital FM Summertime Ball

Watch Justin Bieber Perform 'Boyfriend' (Full) at the Capital FM Summertime Ball

Watch Justin Bieber Perform 'Die In Your Arms' at the Capital FM Summertime Ball

Watch Justin Bieber Perform 'All Around the World' at the Capital FM Summertime Ball

Watch Justin Bieber Perform 'Baby' at the Capital FM Summertime Ball

Watch Justin Bieber Perform 'Somebody to Love' at the Capital FM Summertime Ball