This poor girl didn't stand a chance!

Justin Bieber and his buds showed up for a SoulCycle class this morning in Beverly Hills, and the session must have been full, because The Biebs flirted up a storm with the front desk girl as he secured their place on the list!

In case you're impatient, fast forward to the .50 second mark... you can literally see JB giving the employee Bieber fever with his eyes! He of all people knows that the fever is highly contagious and usually terminal, so he really should be more careful about just spreading it around!

The jolt of endorphins must have been just what he needed, because he left his workout sweaty and smiling! Oh, and because he was in such a good mood, we asked him about pal Conor McGregor's arrest for a fight at Barclay's Center in New York on Thursday and he told us, "We all make mistakes." Watch!