Nine Muses had been hinting that they would be making a comeback very soon and they finally released a teaser music video for 'Glue'. 

SEE ALSO: NewJeans' parents were reportedly the first to raise concerns over ILLIT copying the group

The teaser image that was posted few days ago stated that it is rated for people over 25 years of age! Most people are familiar with the 19+ rating, which is considered equivalent to Mature, so what could possibly be 25+?  

The girls give a hint at why they're rating it 25+ as they look very sexy in the teaser video. The digital single is set to be released on December 4 at noon KST.  Let's see what new image Nine Muses has in store for their fans!