The tables turned on Justin Bieber when he sat down with Ellen DeGeneres [1] on Friday. Although the pair usually teams up to scare people together [2], Ellen decided to prank Justin this time. Midinterview, as she asked Justin about the upcoming Comedy Central roast, a man in Calvin Klein underwear (of course) popped out of a box designed to look like a table beside Justin's chair. The singer freaked out, screaming before saying, "Why me? I'm the prankster!" Ellen joked, "He was trying to be as good-looking as you." Watch the funny clip above, and then get a quick refresher on 21 things they'll probably mention in the Justin Bieber roast [3].