"You Do Know What the Lollipop Is For" is the fourth episode of the tenth season of Two and a Half Men , featuring Miley Cyrus as guest star Missi. The episode centers on Walden's struggle with aging and Jake's romantic interest in Missi, with the title referring to a joke about dental practices. For more details, visit Two and a Half Men Wiki . You Do Know What The Lollipop Is For