Shields ended up posting a video of the behind-the-scenes ball-busting "fun" on Twitter and Youtube.
We guess A.J. wanted it that way.
In any case, when he's not protecting his privates, McLean and his fellow Backstreeters are gearing up to celebrate their 20th anniversary on April 20 by dropping a new album. Two days later, the world's best-selling boy band is set to receive their own star on the Hollywood Walk of Fame, and they'll follow that up in May by kicking off a world tour in Beijing.