LOS ANGELES (TheWrap.com) – Justin Bieber is about to get even more two-dimensional than some people already consider him to be. "Baby" and "Boyfriend" singer Bieber will appear in a cameo in the upcoming season of "The Simpsons," Fox told TheWrap. Bieber broke the news Tuesday in a tweet, since deleted, that revealed, "just did a voice over for the SIMPSONS!!! #swaggy." "Simpsons" executive producer Al Jean told EW.com that Bieber will unsuccessfully try to enter a talent show in which Bart Simpson is performing. The episode, titled "The Fabulous Faker Boy," will air next year, EW.com said. …