2x10 - Teen Titans

Terra and Beast Boy are finally kicking up a notch when they go out on a date. But while they were out, someone let Slade's army into Titans Tower. But when Beast Boy and Terra just about kiss, Slade ruins the romance. Slade lets out the news that Terra is his apprentice, making for a very unhappy Beast Boy. Finally, he turns his back on Terra, letting her go with Slade.