'Knowing Brothers' has revealed a preview for next week's episode featuring MAMAMOO.

In the preview, MAMAMOO are back together after 3 years, and they reveal behind-the-scenes stories, including when the members got into a fight. They also compete for the fastest buttoner, share mini covers of other artists, and try to beat quizzes.

In other news, MAMAMOO are making a comeback with 'MIC ON' on October 11.

Watch MAMAMOO's preview of 'Knowing Brothers' above.